Phytase in non-ruminant animal nutrition: a critical review on phytase activities in the gastrointestinal tract and influencing factors

Impact of phytase supplementation on nutrient variability, growth, and digestibility in weaned pigs fed a corn-SBM complex diet

This study evaluated the effects of different nutrient matrices, with or without phytase supplementation, on growth performance, nutrient digestibility, ileal amino acid (AA) digestibility, and blood inositol in pigs fed a complex diet based on corn-soybean meal. Four hundred newly weaned cross-bred (Landrace × Yorkshire × Duroc) 21-day-old piglets of initial body weight 6.35 ± 1.91 kg were allotted to one of the five dietary treatments: Control (CNT), a corn-soybean-based standard diet; negative control 1 (NC1), a standard diet with reduced available phosphorus (Av.P) (-0.125%), metabolizable energy (ME) (-40 kcal), and crude protein (CP) (-0.3%); NC1 with 500 phytase units per kilogramme (FTU/kg) (N1P5); negative control 2 (NC2), a standard diet with greater reduction of Av.P (-0.150%), ME (-55 kcal), and CP (-0.45%,); and NC2 with 1000 FTU/kg (N2P10). Piglets were housed in a random arrangement based on sex and body weight and data were analyzed as a randomized complete block design using analysis of variance. Results showed that the body weight and average daily gain of the NC2 treatment were lower (p < 0.05) compared to NC2. Gain to feed ratio was greater (p < 0.05) in the CNT and N1P5 treatments compared to the NC1, NC2, and N2P10 treatments. The CP digestibility was higher (p < 0.05) in N1P5 and N2P10 treatments compared to other treatments. Moreover, the digestibility of phosphorus and calcium was higher (p < 0.05) in N1P5 and N2P10 treatments than in CNT, NC1, and NC2 treatments. The digestibility of non-dispensable AA; histidine, isoleucine, leucine, phenylalanine, and valine were increased (p < 0.05) in N1P5 and N2P10 than in CNT, NC1, and NC2 treatments. Nevertheless, the digestibility of dispensable AA, glutamic acid, was higher (p < 0.05) in N1P5 and N2P10 treatments than in CNT, NC1, and NC2 treatments. Blood myo-inositol concentration was higher (p < 0.05) in N1P5 and N2P10 treatments compared to CNT, NC1, and NC2 treatments in phase 2. These results demonstrated enhanced outcomes under conditions of moderate deficiency, whereas more pronounced deficiencies necessitated increased phytase dosages to observe significant improvements. The efficacy of phytase was evident in its ability to elevate average daily gain, gain to feed ratio, phosphorus and calcium, CP, AA, and blood myo-inositol.

Effects of dietary calcium and microbial phytase on the bioavailability of two sources of zinc in broilers

1. The objective of this study was to test the effect of microbial phytase and calcium (Ca) levels on the Zn bioavailability depending on the Zn source.2. A total of 144, one-day-old broilers received a diet containing 40 mg Zn/kg for 1 week. They were then assigned to one of the eight experimental treatments during 2 weeks. Diets contained 27 mg native Zn and were formulated according to a 2 × 2 × 2 factorial design with two added Zn sources (23 mg Zn/kg), sulphate (ZnSO4) or oxide (ZnO); two dietary Ca levels of either 6 (low) or 10 g/kg (moderate); and two microbial phytase levels, of either 0 or 750 phytase unit/kg.3. Moderate Ca plus phytase improved body weight gain (BWG) and low Ca level without microbial phytase decreased tibia weight (Ca × Phy; p = 0.049). Zinc oxide resulted in a higher tibia development (i.e. tibia weight and length; p < 0.05) and BWG (p = 0.009) and lower FCR (p < 0.001) compared to ZnSO4.4. Phytase improved tibia Zn concentration especially in birds given ZnSO4 compared to ZnO (Zn × Phy; p = 0.049). Moderate Ca diets improved tibial characteristics and Zn deposition compared to low Ca diets (p < 0.05).5. Soluble Zn in the gizzard increased in the presence of phytase (p = 0.011), while higher dietary Ca reduced this in birds receiving ZnO (p = 0.004). In the jejunum, Zn solubility was higher with phytase (p = 0.008).6. Under the conditions of this study, dietary levels of Ca and microbial phytase affect Zn availability in broilers more than the Zn source.

Response of YPM x Ross 708 male broilers to diets containing varying inclusions of phytase, calcium butyrate, and bacitracin methylene disalicylate from 1 to 42 d of age-part 1: performance, processing yields, and nutrient digestibility

This 42-d study evaluated the effects of phytase, calcium butyrate (CB), and bacitracin methylene disalicylate 50 (BMD) on broiler performance, processing yields, and nutrient digestibility. Ross YPM x 708 male broilers (2,880 total) were distributed in 72 floor pens and assigned to 1 of 9 treatments (8 replicates/treatment) on d of hatch. This experiment was a 2 × 4 + 1 factorial arrangement, including 2 phytase concentrations (500 or 1,500 FTU/kg), 4 microbiota modulating feed additive groups (MMFA; none, CB (0.5 g/kg of diet), BMD (55 mg/kg of diet), or both CB and BMD), and a negative control without feed additives. Broiler performance (d 14, 28, and 42), apparent ileal nutrient digestibility (d 28 and 42), and processing yields (d 43) were determined. Day 14 BW increased with BMD inclusion compared to CB and no MMFA in the 1,500 FTU/kg group but BW were similar between all MMFA combined with 500 FTU/kg (P ≤ 0.05). Supplementing BMD increased d 28 BW and reduced d 1 to 28 feed conversion ratio compared to CB and no MMFA (main effect, P ≤ 0.05). Day 42 BW varied depending on dietary phytase concentrations. When diets contained 500 FTU/kg, broilers fed both CB and BMD had a higher BW than broilers fed only CB. Whereas when the inclusion of phytase was increased to 1,500 FTU/kg, broilers fed diets with only BMD or both CB and BMD had higher BW than broilers fed diets with no MMFA (P ≤ 0.05). Phytase concentrations at 1,500 FTU/kg increased (P ≤ 0.05) digestibility of fat (main effect, d 42), phosphorus (d 28 and 42), and apparent ileal digestible energy (main effect, d 42) compared to 500 FTU/kg. In this study, dietary BMD improved broiler growth compared to CB and no MMFA. However, these observed differences between CB and BMD were dependent on dietary phytase concentrations.

Effects of Dietary Supplementation of Quillaja Saponin or Phytase on the Growth Performance, Nutrient Digestibility, Faecal Gas Emissions, and Carcass Grade in Growing-Finishing Pigs

This experiment aimed to evaluate the effects of low doses of Quillaja saponin (QS) or phytase (PHY) on growth performance, nutrient digestibility, faecal gas emissions, and carcass grade in growing-finishing pigs. A total of 72 pigs (Landrace × Yorkshire × Duroc), each weighing 25.82 ± 1.68 kg, were selected and randomly assigned to three treatment groups. Each group had six replicates, with four pigs per pen, and the allocation was based on the four initial body weight and sex of the pigs. They were randomly divided into the following three diet groups: the basal diet as a control (CON) group, the basal diet + 0.02% PHY; and the basal diet + 0.01% QS. The experiment period lasted for 110 days. The results of adding 0.01% QS to the basal diet of pigs show that it can significantly increase the body weight (BW) of growing-finishing pigs on the 110th day (p < 0.05). QS can significantly increase the average daily weight gain (ADG) on Days 80-110 of the experiment (p < 0.05). QS can significantly increase the total average daily weight gain (TADG) of growing-finishing pigs during the entire experimental period (p < 0.05) and has a tendency to improve the average daily feed intake and feed conversion rate during the entire experimental period. However, QS has no significant effect on pig nutrient digestibility and carcass grade. In addition, we also found that QS has a tendency to reduce carbon dioxide emissions. However, adding 0.02% PHY to the basal diet of growing-finishing pigs can only increase the TADG during the entire experimental period. Throughout the experiment, adding PHY to the diet had no significant impact on the nutrient digestibility, faecal gas emissions, and carcass grade of growing-finishing pigs. In summary, adding QS to feed can significantly improve the growth performance of growing-finishing pigs, and has a tendency to improve faecal gas emissions. PHY can only improve the growth performance of growing-finishing pigs.

Dose of phytase from either Aspergillus niger or Escherichia coli on performance of nursery piglets

Supplementing swine diets with phytase increases phosphorus release by approximately 50% from cereal phytates. The increase in phosphorus availability allows for a reduction in dietary phosphorus supplementation from mineral sources and decreases the environmental impact of pork production through a decrease in phosphorus excretion. Superdosing phytase has been reported to boost swine productivity, improve the digestibility of other nutrients, and mitigate the antinutritional effects of phytates. However, there are significant cost differences among phytase products. Bacterial phytases are considered more modern, often with a higher cost of inclusion. A study was conducted with 288 piglets that were 21 d of age and weighed 6.43 ± 0.956 kg. Pigs were divided into four groups. Each group of pigs was fed a different experimental diet varying in phytase source and level: fungal phytase (Aspergillus niger) at 500 FTU/kg of diet, fungal phytase at 2,000 FTU/kg, bacterial phytase (Escherichia coli) at 500 FTU/kg, and bacterial phytase at 2,000 FTU/kg. No differences were found for phytase sources or doses on productivity at 14 and 21 d postweaning. However, piglets supplemented with 2,000 FTUs/kg of phytase in the diet during the first 21 d of nursery exhibited a 5.8% better feed conversion (P = 0.02). An interaction between phytase source and dose was observed for average live weight and daily weight gain over the 42-d nursery period (P < 0.05). Supplementing the diet with 2,000 FTU/kg of fungal phytase improved daily weight gain and live weight throughout the experimental period compared to piglets supplemented with 500 FTU/kg of the same phytase source. Additionally, it resulted in better final weights compared to piglets supplemented with 500 FTU/kg of bacterial phytase. Phytase inclusion at 2,000 FTU/kg improved feed conversion by 2.07% over the 42-d nursery period. The most economically favorable feed conversion ratios were observed when supplementing the diet with fungal phytase at 2,000 FTUs/kg.

Production, purification and characterization of phytase from Pichia kudriavevii FSMP-Y17and its application in layers feed

INTRODUCTION

Phytase, recognized for its ability to enhance the nutritional value of phytate-rich foods, has has gained significant prominence. The production of this enzyme has been significantly boosted while preserving economic efficiency by utilizing natural substrates and optimizing essential factors. This study focuses on optimizing phytase production through solid-state fermentation and evaluating its effectiveness in enhancing nutrient utilization in chicken diets.

OBJECTIVE

The objective is to optimize phytase production via solid-state fermentation, characterize purified phytase properties, and assess its impact on nutrient utilization in chicken diets. Through these objectives, we aim to deepen understanding of phytase's role in poultry nutrition and contribute to more efficient feed formulations for improved agricultural outcomes.

METHODOLOGY

We utilized solid-state fermentation with Pichia kudriavzevii FSMP-Y17 yeast on orange peel substrate, optimizing variables like temperature, pH, incubation time, and supplementing with glucose and ammonium sulfate. Following fermentation, we purified the phytase enzyme using standard techniques, characterizing its properties, including molecular weight, optimal temperature and pH, substrate affinity, and kinetic parameters.

RESULTS

The optimized conditions yielded a remarkable phytase yield of 7.0 U/gds. Following purification, the enzyme exhibited a molecular weight of 64 kDa and displayed optimal activity at 55 °C and pH 5.5, with kinetic parameters (Km = 3.39 × 10-3 M and a Vmax of 7.092 mM/min) indicating efficient substrate affinity.

CONCLUSION

The addition of purified phytase to chicken diets resulted in significant improvements in nutrient utilization and overall performance, including increased feed intake, improved feed conversion ratio, enhanced bird growth, better phosphorus retention, and improved egg production and quality. By addressing challenges associated with phytate-rich diets, such as reduced nutrient availability and environmental pollution, phytase utilization promotes animal welfare and sustainability in poultry production.

Unlocking Phytate with Phytase: A Meta-Analytic View of Meat-Type Chicken Muscle Growth and Bone Mineralization Potential

The inclusion of exogenous phytase in P- and Ca-deficient diets of broilers to address the growing concern about excessive P excretion into the environment over the years has been remarkably documented. However, responses among these studies have been inconsistent because of the several factors affecting P utilization. For this reason, a systematic review with a meta-analysis of results from forty-one studies published from 2000 to February 2024 was evaluated to achieve the following: (1) quantitatively summarize the size of phytase effect on growth performance, bone strength and mineralization in broilers fed diets deficient in P and Ca and (2) estimate and explore the heterogeneity in the effect size of outcomes using subgroup and meta-regression analyses. The quality of the included studies was assessed using the Cochrane Collaboration's SYRCLE risk of bias checklists for animal studies. Applying the random effects models, Hedges' g effect size of supplemented phytase was calculated using the R software (version 4.3.3, Angel Food Cake) to determine the standardized mean difference (SMD) at a 95% confidence interval. Subgroup analysis and meta-regression were used to further explore the effect size heterogeneity (PSMD ≤ 0.05, I2 > 50%, n ≥ 10). The meta-analysis showed that supplemental phytase increases ADFI and BWG and improves FCR at each time point of growth (p < 0.0001). Additionally, phytase supplementation consistently increased tibia ash, P and Ca, and bone strength (p < 0.0001) of broilers fed P- and Ca-deficient diets. The results of the subgroup and meta-regression analyses showed that the age and strain of broiler, dietary P source, and the duration of phytase exposure significantly influence the effect size of phytase on growth and bone parameters. In conclusion, phytase can attenuate the effect of reducing dietary-available phosphorus and calcium and improve ADFI, BWG, and FCR, especially when added to starter diets. It further enhances bone ash, bone mineralization, and the bone-breaking strength of broilers, even though the effects of bone ash and strength can be maximized in the starter phase of growth. However, the effect sizes of phytase were related to the age and strain of the broiler, dietary P source, and the duration of phytase exposure rather than the dosage.

Impacts of Maternal Nutrition on Sow Performance and Potential Positive Effects on Piglet Performance

The objectives of this review are to identify the nutritional challenges faced by modern sows and present potential solutions to mitigate excessive maternal tissue loss and reproductive failure as it relates to recent genetic improvements. Current feeding programs have limitations to support the rapid genetic improvements in reproductive performance for modern sows. Since 2012, both litter size at birth and fetal weight have increased by 2.26 pigs per litter and 0.22 kg per piglet, respectively, thereby increasing the nutrient needs for sows during gestation and lactation. Prediction models generated in this review predict that modern sows would need 31% more lysine during gestation when compared with current feeding programs. Physiological challenges facing modern sows are also addressed in this review. High oxidative stress, pelvic organ prolapse, and lameness can directly affect the sow, whereas these physiological challenges can have negative impacts on colostrum and milk quality. In response, there is growing interest in investigating the functional roles of select bioactive compounds as feed additives to mitigate the severity of these challenges. Selenium sources, catechins, and select plant extracts have been utilized to reduce oxidative stress, calcium chloride and phytase have been used to mitigate pelvic organ prolapse and lameness, algae and yeast derivatives have been used to improve colostrum and milk quality, and fiber sources and probiotics have been commonly utilized to improve sow intestinal health. Collectively, this review demonstrates the unique challenges associated with managing the feeding programs for modern sows and the opportunities for revision of the amino acid requirements as well as the use of select bioactive compounds to improve reproductive performance.

Review on Desirable Microbial Phytases as a Poultry Feed Additive: Their Sources, Production, Enzymatic Evaluation, Market Size, and Regulation

Poultry's digestive tract lacks hydrolytic phytase enzymes, which results in chelation of dietary minerals, vital amino acids, proteins, and carbohydrates, phytate-phosphate unavailability, and contamination of the environment due to phosphorus. Therefore, it is necessary to use exogenous microbial phytases as feed additive to chicken feed to catalyze the hydrolysis of dietary phytate. Potential sources of microbial isolates that produce desired phytases for chicken feed supplementation have been isolated from agricultural croplands. It is achievable to isolate phytase-producing bacteria isolates using both broth and agar phytase screening media. Potential substrates for submerged fermentation (SmF) for bacterial phytase production and solid-state fermentation (SSF) for fungal phytase production include rice and wheat bran. Following fermentation, saturated ammonium sulphate precipitation is typically used to partially purify microbial culture filtrate. The precipitate is then desalted. Measurements of the pH optimum and stability, temperature optimum and stability, metal ions stability, specificity and affinity to target substrate, proteolysis resistance, storage stability, and in vitro feed dephosphorylation are used to perform an enzymatic evaluation of phytase as an additive for poultry feed. The growth of the feed phytase market is primarily due to the expansion of chicken farms to meet the demand for meat and eggs from humans. The Food and Drug Administration in the USA and the European Food and Safety Authority are primarily in charge of putting rules pertaining to feed phytase use in chicken feed into effect. Conclusively, important components of the production of phytase additives for poultry feed include identifying a reliable source for potential microbe isolation, selecting an economical method of phytase production, thoroughly characterizing the biochemical properties of phytase, and comprehending the size and regulation of the current feed phytase market.

Effects of a Novel Consensus Bacterial 6-Phytase Variant on Growth Performance and Bone Ash of Broilers Fed Complex Diets Highly Deficient in Minerals, Digestible Amino Acids and Energy through 42 Days of Age

An experiment was conducted to evaluate the effects of increasing the dose of a novel consensus bacterial 6-phytase variant expressed in Trichoderma reesei (PhyG) in broilers fed complex diets highly deficient in minerals, dig AA, and energy. Diets were a nutrient-adequate control (PC); a nutrient-reduced control (NC) formulated with a reduction in available P (avP) by 0.199%, Ca by 0.21%, crude protein by 0.72-1.03%, dig Lys by 0.064-0.084%, Na by 0.047%, and ME by 87.8 kcal/kg, respectively; and NC supplemented with PhyG at 500, 1000, and 2000 FTU/kg feed. BW was decreased and FCR increased in the NC vs. PC, while the PhyG treatments were similar to the PC. Carcass yield and bone ash were also maintained with PhyG supplementation. Phytase provided economic benefit on a feed cost per kg of weight basis for 1 to 35 d; the cost reductions equated to USD 0.006, 0.016, and 0.02/kg BWG at 500, 1000, and 2000 FTU/kg. In conclusion, this trial demonstrated that supplementation with a novel consensus phytase variant in diets highly deficient in minerals, dig AA, and energy maintained growth performance and provided economic benefit, with production benefits being maximized at inclusion levels of 2000 FTU/kg.

Comparative effects of proteases on performance, carcass traits and gut structure of broilers fed diets reduced in protein and amino acids

This study aimed to evaluate the effect of supplementing different protease enzymes on growth performance, intestinal morphology, and selected carcass traits in broilers fed diets reduced 3.5% in crude protein (CP) and amino acids (AA). One thousand one-day-old Ross 308 broilers (41 g) were assigned to five dietary treatments with ten replicates of 20 birds each: a positive control (PC) diet formulated to meet Ross 308 AA requirements, a negative control (NC) diet reformulated to provide 3.5% lower CP and AA compared to PC, NC supplemented with a multi-protease (PR1) solution, containing 3 different coated proteases produced from Aspergillus niger, Bacillus subtilis and Bacillus licheniformis, NC supplemented with a serine protease (PR2) produced from Bacillus licheniformis, and NC supplemented with an alkaline protease (PR3) produced from Bacillus licheniformis. At slaughter, 40 birds per treatment were used to assess the effect of the different treatments on carcass traits. At 32 days, samples of the duodenum, jejunum, and ileum of 10 birds per treatment were collected for intestinal morphology evaluation. Birds fed PC and NC supplemented with multi-protease exhibited better (p < 0.05) feed efficiency compared to NC and NC supplemented with all the other protease enzymes. Multi-protease supplementation was linked to the highest (p < 0.05) carcass weight and yield. There were significant differences (p < 0.05) between treatments in all gut segments, with PC, PR1, PR2, and PR3 exhibiting longer villi height (VH) compared to NC. This study demonstrates that 3.5% reduction of CP and AA negatively affected for the overall period feed efficiency, carcass yield, and intestinal morphology. The supplementation of the multi-protease restored feed efficiency and improved carcass yield.

In vitro digestibility and solubility of phosphorus of three plant-based meat analogues

Interest in plant-based meat analogues has increased and can be expected to be applied to pet foods, which necessitates the understanding of the nutrient supply in those foods. Our primary aim was to advance our understanding of the digestive properties of sterilized plant-based meat analogues. The impact of the preparatory processing steps on the solubility of meat analogues was studied. Meat analogues were made by mixing water, salt, and wheat gluten with soy protein isolate, pea protein isolate, or faba bean concentrate. Mixed materials were processed into model meat analogues using shear cell technology. Products were canned in water or gravy and sterilized. An animal-based canned pet food was made as a reference. Products sampled at the processing steps (mixing, shearing, sterilization) were digested in vitro. Samples of digestate were taken at the gastric phase (0 and 120 min) and small intestinal phase (120, 200, 280, and 360 min) for analysis of protein hydrolysis. The extent digestion of nitrogen and dry matter was determined at the end of incubation. Total phosphorus, soluble phosphorus after acid treatment, and after acid and enzymatic treatment were determined. The degree of hydrolysis after gastric digestion was low but increased immediately in the small intestinal phase; products based on pea had the highest values (56%). Nitrogen digestibility was above 90% for all materials at each processing step, indicating that bioactive compounds were absent or inactivated in the protein isolates and concentrate. Phytate seemed to play a minor role in meat analogues, but phosphorus solubility was influenced by processing. Shearing decreased soluble phosphorus, but this effect was partly reversed by sterilization. Nutrient digestibility as well as phosphorus solubility in plant-based products was higher than or comparable with the reference pet food. These findings show that the digestive properties of the tested plant-based meat analogues do not limit the supply of amino acids and phosphorus.

Surface Engineering of Escherichia coli to Display Its Phytase (AppA) and Functional Analysis of Enzyme Activities

Escherichia coli phytase (AppA) is widely used as an exogenous enzyme in monogastric animal feed mainly because of its ability to degrade phytic acid or its salt (phytate), a natural source of phosphorus. Currently, successful recombinant production of soluble AppA has been achieved by gene overexpression using both bacterial and yeast systems. However, some methods for the biomembrane immobilization of phytases (including AppA), such as surface display on yeast cells and bacterial spores, have been investigated to avoid expensive enzyme purification processes. This study explored a homologous protein production approach for displaying AppA on the cell surface of E. coli by engineering its outer membrane (OM) for extracellular expression. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis of total bacterial lysates and immunofluorescence microscopy of non-permeabilized cells revealed protein expression, whereas activity assays using whole cells or OM fractions indicated functional enzyme display, as evidenced by consistent hydrolytic rates on typical substrates (i.e., p-nitrophenyl phosphate and phytic acid). Furthermore, the in vitro results obtained using a simple method to simulate the gastrointestinal tract of poultry suggest that the whole-cell biocatalyst has potential as a feed additive. Overall, our findings support the notion that biomembrane-immobilized enzymes are reliable for the hydrolysis of poorly digestible substrates relevant to animal nutrition.

Functional expression, purification, biochemical and biophysical characterizations, and molecular dynamics simulation of a histidine acid phosphatase from Saccharomyces cerevisiae

A histidine acid phosphatase (HAP) (PhySc) with 99.50% protein sequence similarity with PHO5 from Saccharomyces cerevisiae was expressed functionally with the molecular mass of ∼110 kDa through co-expression along with the set of molecular chaperones dnaK, dnaJ, GroESL. The purified HAP illustrated the optimum activity of 28.75 ± 0.39 U/mg at pH 5.5 and 40 ˚C. The Km and Kcat values towards calcium phytate were 0.608 ± 0.09 mM and 650.89 ± 3.6 s- 1. The half-lives (T1/2) at 55 and 60 ˚C were 2.75 min and 55 s, respectively. The circular dichroism (CD) demonstrated that PhySc includes 30.5, 28.1, 21.3, and 20.1% of random coils, α-Helix, β-Turns, and β-Sheet, respectively. The Tm recorded by CD for PhySc was 56.5 ± 0.34˚C. The molecular docking illustrated that His59 and Asp322 act as catalytic residues in the PhySc. MD simulation showed that PhySc at 40 ˚C has higher structural stability over those of the temperatures 60 and 80 ˚C that support the thermodynamic in vitro investigations. Secondary structure content results obtained from MD simulation indicated that PhySc consists of 34.03, 33.09, 17.5, 12.31, and 3.05% of coil, helix, turn, sheet, and helix310, respectively, which is almost consistent with the experimental results.

Improving the thermal stability of phytase using core-shell hydrogel beads

A core-shell hydrogel bead system was designed to maintain the catalytic activity of phytase and protect its enzymatic functionality from heat treatment. The designed structure consists of a chitosan-phytase complex core and an alginate-carrageenan hydrogel shell. The core-shell hydrogel was optimized to improve phytase encapsulation efficiency and increase the thermal stability of the encapsulated phytase. After heat treatment, encapsulated phytase retained ∼ 70 % of its catalytic activity and the same secondary structure of free phytase. Fourier transform infrared spectroscopy indicated strong intermolecular interactions between chitosan and phytase in the core, but little interaction between the core and the alginate and κ-carrageenan shell, this supports the structural and functional stability of the phytase. Differential scanning calorimetry confirmed that the designed core-shell structure had a higher melting point. Encapsulating phytase in a core-shell hydrogel bead can enhance the thermal stability of phytase, which broadens the potential applications for phytase delivery.

Carbohydrases and Phytase in Poultry and Pig Nutrition: A Review beyond the Nutrients and Energy Matrix

This review aimed to clarify the mechanisms through which exogenous enzymes (carbohydrases and phytase) influence intestinal health, as well as their effects on the nutrients and energy matrix in diets fed to poultry and pigs reared under sanitary challenging conditions. Enzyme supplementation can positively affect intestinal microbiota, immune system, and enhance antioxidant status. Although enzymes have been shown to save energy and nutrients, their responses under sanitary challenging conditions are poorly documented. Immune system activation alters nutrient partitioning, which can affect the matrix values for exogenous enzymes on commercial farms. Notably, the carbohydrases and phytase supplementation under sanitary challenging conditions align with energy and nutritional valorization matrices. Studies conducted under commercial conditions have shown that matrices containing carbohydrases and phytase can maintain growth performance and health in poultry and pigs. However, these studies have predominantly focused on assessing a single level of reduction in energy and/or available phosphorus and total calcium, limiting our ability to quantify potential energy and nutrient savings in the diet. Future research should delve deeper into determining the extent of energy and nutrient savings and understanding the effects of alone or blended enzymes supplementation to achieve more specific insights.

A study of solely used phytase or in combination with multi-carbohydrase on growth performance along with tibia mineralization, and carcass traits in broilers fed nutrient-deficient diets

The objective of this study aimed to investigate the effectiveness of phytase alone and in combination with multi-carbohydrase in available phosphorus (AP) and energy-deficient diets on growth performance, nutrient digestibility, tibia traits, and carcass quality of broilers. A total of 288 1-d-old Ross 308 broiler chicks were randomly assigned to one of 6 dietary treatments in a completely randomized design, with each treatment having 6 replicates and 8 birds per cage. The treatments were as follows: 1) positive control with adequate nutrition (PC); 2) 0.20% AP-deficient diet without phytase (NC-1); 3) 0.25% AP-deficient diet without phytase (NC-2); 4) NC-1 diet plus 500 FTU/kg phytase (NCP-1); 5) NC-2 diet plus 750 FTU/kg phytase (NCP-2); and 6) NC-2 with 100 kcal/kg ME deficient diet plus 1,000 FTU/kg phytase and multi-carbohydrase: 2,200 U/kg galactomannanase, 30,000 U/kg xylanase, 22,000 U/kg β-glucanase, and 700 U/kg α-galactosidase (NCPM). Broilers in the PC group and those fed enzyme-supplemented diets exhibited greater (P < 0.05) growth performance in terms of body weight, average daily gain, and feed conversion ratio, along with enhanced tibia mineralization through the ash, calcium (Ca), phosphorus (P) composition, and tibia breaking strength compared to NC diets throughout the study. Among the treatments, broilers assigned to the NCPM group showed greater (P < 0.05) levels of energy and P digestibility on days 21 and 35. Concerning carcass characteristics, the leg meat yield was greater (P < 0.05) in broilers fed the NCP-2 diet compared to all other treatments on days 21 and 35. Supplementation of phytase at doses of 500 FTU/kg and 750 FTU/kg effectively recovers AP deficiencies of 0.20% and 0.25%, respectively, in broiler diets without compromising the growth performance of broilers. Additionally, combining multi-carbohydrase and phytase led to AP and energy loss recovery, which improved tibia mineralization and nutrient digestibility through their synergistic interaction.

Determining the phosphorus release curve for Sunphase HT phytase in nursery pig diets

A total of 280 pigs (DNA 241 × 600, initially 10.4 ± 0.24 kg) were used in a 21-d study to determine the available P (aP) release curve for Sunphase HT phytase (Wuhan Sunhy Biology Co., Ltd., Wuhan, P.R. China) when fed diets with a high phytate concentration. On day 21 post-weaning, considered day 0 of the study, pigs were blocked by average pen body weight (BW) and randomly allotted to 1 of 7 dietary treatments with 5 pigs per pen and 8 pens per treatment. Dietary treatments were derived from a single basal diet, and ingredients including phytase, monocalcium P, limestone, and sand were added to create the treatment diets. Treatments included three diets with increasing (0.11%, 0.19%, and 0.27%) aP from monocalcium P, or four diets with increasing phytase (250, 500, 1,000, or 2,000 phytase unit (FTU)/kg) added to the diet formulated to 0.11% aP. All diets were corn-soybean meal-canola meal-based and were formulated to contain 1.24% SID Lys, a 1.10:1 total calcium-to-phosphorus ratio, and a calculated 0.32% phytate P. Prior to the beginning of the study, all pigs were fed a diet containing 0.11% aP from days 18 to 21 post-weaning. At the conclusion of the study, 1 pig, closest to the mean weight of each pen, was euthanized, and the right fibula, 10th rib, and metacarpal were collected to determine bone ash and density. After cleaning, bones were submerged in ultra-purified water under a vacuum for 4 h and then weighed to calculate the density (Archimedes principle). For bone ash, bones were processed using the non-defatted method. From days 0 to 21, increasing aP from monocalcium P increased (linear, P ≤ 0.014) average daily gain (ADG), gain-to-feed (G:F), and final BW. Pigs fed increasing phytase had increased (linear, P ≤ 0.045) ADG, final BW, and plasma inositol concentration as well as improved (quadratic, P = 0.023) G:F. For bone characteristics, pigs fed increasing aP from inorganic P had a linear improvement (P ≤ 0.019) in fibula bone ash weight and percentage bone ash, rib bone ash weight and bone density, and all metacarpal bone properties, with a quadratic response (P ≤ 0.030) for fibula bone density and rib percentage ash. Additionally, pigs fed increasing phytase had increased (P < 0.05) bone ash weight, percentage bone ash, and bone density in either a linear or quadratic fashion depending on the bone analyzed. The available P release curve generated for Sunphase HT phytase for percentage bone ash combining values from the right fibula, 10th rib, and metacarpal is aP release, % = (0.360 × FTU) ÷ (2,330.250 + FTU).

Interactions of zinc with phytate and phytase in the digestive tract of poultry and pigs: a review

Phytase supplementation is gaining importance in animal nutrition because of its effect on phosphorus (P) digestibility and the increasing relevance of P for sustainable production. The potential inhibitors of phytase efficacy and phytate degradation, such as calcium (Ca) and zinc (Zn), have been a subject of intense research. This review focuses on the interactions of Zn with phytate and phytase in the digestive tract of poultry and pigs, with an emphasis on the effects of Zn supplementation on phytase efficacy and P digestibility. In vitro studies have shown the inhibitory effect of Zn on phytase efficacy. However, relevant in vivo studies are scarce and do not show consistent results for poultry and pigs. The results could be influenced by different factors, such as diet composition, amount of Zn supplement, mineral concentrations, and phytase supplementation, which limit the comparability of studies. The chosen response criteria to measure phytase efficacy, which is mainly tibia ash, could also influence the results. Compared to poultry, the literature findings are somewhat more conclusive in pigs, where pharmacological Zn doses (≥ 1000 mg kg-1 Zn) appear to reduce P digestibility. To appropriately evaluate the effects of non-pharmacological Zn doses, further studies are needed that provide comprehensive information on their experimental setup and include measurements of gastrointestinal phytate degradation to better understand the mechanisms associated with Zn and phytase supplements. © 2023 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Jejunal microbiota of broilers fed varying levels of mineral phosphorus

Efforts to achieve sustainable phosphorus (P) inputs in broiler farming which meet the physiological demand of animals include nutritional intervention strategies that have the potential to modulate and utilize endogenous and microbiota-associated capacities. A temporal P conditioning strategy in broiler nutrition is promising as it induces endocrinal and transcriptional responses to maintain mineral homeostasis. In this context, the current study aims to evaluate the composition of the jejunal microbiota as a functional entity located at the main absorption site involved in nutrient metabolism. Starting from a medium or high P supply in the first weeks of life of broilers, a depletion strategy was applied at growth intervals from d 17 to 24 and d 25 to 37 to investigate the consequences on the composition of the jejunal microbiota. The results on fecal mineral P, calcium (Ca), and phytate contents showed that the diets applied to the depleted and non-depleted cohorts were effective. Microbial diversity in jejunum was represented by alpha diversity indices which appeared unaffected between dietary groups. However, chickens assigned to the dietary P depletion groups showed significantly higher abundances of Facklamia, Lachnospiraceae, and Ruminococcaceae compared to non-depleted control groups. Based on current knowledge of microbial function, these microorganisms make only a minor contribution to the birds' adaptive mechanism in the jejunum following P depletion. Microbial taxa such as Brevibacterium, Brachybacterium, and genera of the Staphylococcaceae family proliferated in a P-enriched environment and might be considered biomarkers for excessive P supply in commercial broiler chickens.

Improving phytase production in Pichia pastoris fermentations through de-repression and methanol induction optimization

Pichia pastoris (Komagataella phaffii) is a fast-growing methylotrophic yeast with the ability to assimilate several carbon sources such as methanol, glucose, or glycerol. It has been shown to have outstanding secretion capability with a variety of heterologous proteins. In previous studies, we engineered P. pastoris to co-express Escherichia coli AppA phytase and the HAC1 transcriptional activator using a bidirectional promoter. Phytase production was characterized in shake flasks and did not reflect industrial conditions. In the present study, phytase expression was explored and optimized using instrumented fermenters in continuous and fed-batch modes. First, the production of phytase was investigated under glucose de-repression in continuous culture at three dilution factors, 0.5 d-1 , 1 d-1 , and 1.5 d-1 . The fermenter parameters of these cultures were used to inform a kinetic model in batch and fed-batch modes for growth and phytase production. The kinetic model developed aided to design the glucose-feeding profile of a fed-batch culture. Kinetic model simulations under glucose de-repression and fed-batch conditions identified optimal phytase productivity at the specific growth rate of 0.041 h-1 . Validation of the model simulation with experimental data confirmed the feasibility of the model to predict phytase production in our newly engineered strain. Methanol was used only to induce the expression of phytase at high cell densities. Our results showed that high phytase production required two stages, the first stage used glucose under de-repression conditions to generate biomass while expressing phytase, and stage two used methanol to induce phytase expression. The production of phytase was improved 3.5-fold by methanol induction compared to the expression with glucose alone under de-repression conditions to a final phytase activity of 12.65 MU/L. This final volumetric phytase production represented an approximate 36-fold change compared to the flask fermentations. Finally, the phytase protein produced was assayed to confirm its molecular weight, and pH and temperature profiles. This study highlights the importance of optimizing protein production in P. pastoris when using novel promoters and presents a general approach to performing bioprocess optimization in this important production host.

Approaches to determine the efficiency of novel 3-phytase from Klebsiella pneumoniae and commercial phytase in broilers from 1 to 14 d of age

This study aimed to evaluate the effects of a laboratory 3-phytase (the expression of the phyK gene, Lab-Phy) and a commercial 6-phytase (Quantum Blue 40 P, Com-Phy) alone and in combination (corn-soy-based diets) in broilers. A total of 400, day-old Ross 308 male broilers were randomly assigned to 5 treatments with 10 replicate cages (8 chicks/cage) for a 14-day trial. Experimental treatments included the positive control (0.95% Ca and 0.48% nonphytate phosphorus (nPP), PC), negative control (0.90% Ca and 0.22% nPP, NC), and NC which was supplemented with Lab-Phy 250 FTU/kg and Com-Phy 250 FTU/kg alone or in combination of Lab-Phy 125 FTU/kg and Com-Phy 125 FTU/kg. The inclusion of Lab-Phy in the NC diet significantly improved the P and Ca content in the tibia compared to the NC group. Moreover, the inclusion of Com-Phy alone and in combination with Lab-Phy in the NC diet significantly increased the P and Ca content in the tibia compared to the Lab-Phy. The mRNA expression of NaPi-IIb was upregulated in the duodenum by the reduction of nPP and downregulated by the inclusion of any phytase, whereas other nutrient transporters were not influenced by the reduction of nPP or the addition of phytase in the small intestine mucosa. Broilers receiving the NC diet obtained the lowest body weight (BW) and body weight gain (BWG) at 8 to 14 and 1 to 14 d of age. The NC group showed the lowest villi height and surface area, Newcastle disease (ND) antibody titer, and digestibility of nutrients compared to the PC group at 14 d of age. Supplementing the NC diet with the Lab-Phy and Com-Phy individually, or in combination tended to improve BW, BWG, tibia characteristics, villi characteristics, ND, and retained CP and P, and apparent ileal digestibility of CP, P, methionine, and threonine. The present research indicated that the studied traits by the combination of phytases were slightly better than the average of the 2 individually, suggesting there might be some value in combining the laboratory and commercial phytases.

Microbial Phytases: Properties and Applications in the Food Industry

Microbial phytases are enzymes that break down phytic acid, an anti-nutritional compound found in plant-based foods. These enzymes which are derived from bacteria and fungi have diverse properties and can function under different pH and temperature conditions. Their ability to convert phytic acid into inositol and inorganic phosphate makes them valuable in food processing. The application of microbial phytases in the food industry has several advantages. Firstly, adding them to animal feedstuff improves phosphorus availability, leading to improved nutrient utilization and growth in animals. This also reduces environmental pollution by phosphorus from animal waste. Secondly, microbial phytases enhance mineral bioavailability and nutrient assimilation in plant-based food products, counteracting the negative effects of phytic acid on human health. They can also improve the taste and functional properties of food and release bioactive compounds that have beneficial health effects. To effectively use microbial phytases in the food industry, factors like enzyme production, purification, and immobilization techniques are important. Genetic engineering and protein engineering have enabled the development of phytases with improved properties such as enhanced stability, substrate specificity, and resistance to degradation. This review provides an overview of the properties and function of phytases, the microbial strains that produce them, and their industrial applications, focusing on new approaches.

A novel consensus bacterial 6-phytase variant improves the responses of laying hens fed an inorganic phosphorus-free diet with reduced energy and nutrients from 23 to 72 wk of age

The objective of this study was to evaluate the effect of a novel consensus bacterial 6-phytase variant (PhyG) on egg productivity, eggshell quality, and body composition of laying hens fed inorganic phosphate-free diets with reduced energy and nutrients from 23 to 72 wk of age. Five treatments were randomly assigned, performing 28 replicates per treatment with 4 hens each, totaling 560 Hy-Line W80 birds. A positive control (PC) feed was formulated to contain adequate levels of energy and nutrients. A negative control (NC) feed was formulated without added inorganic phosphate (0.12% nonphytic phosphorus [nPP]) and reduced in Ca, Na, dig AA, and metabolizable energy in comparison with PC feed. Phytase was supplemented in the NC feed at 0, 300, 600, and 900 FTU/kg of feed. The responses evaluated were performance, egg quality, economic analysis, body composition, and tibia composition. Data were analyzed by a 2-factor (diet and age) repeated measure analysis. Overall, the feed intake, hen-day egg production, egg mass, and egg revenue were reduced by the complete removal of dicalcium phosphate (DCP) (P < 0.05). Supplement phytase in the NC diet elicits a positive response on each one of those variables. Laying hens consuming the NC feed with 900 FTU/kg of phytase produced more eggs per hen-housed compared with the phytase dosages of 300 and 600 FTU/kg. Body composition was not affected by dietary nPP, Ca, Na, dig AA, and energy reductions (P > 0.05). At 72-wk-old, tibia ash was reduced in hens consuming the NC diet vs. PC (P < 0.05) and no difference was observed between hens supplemented with phytase and the PC feed. Margin over feeding cost increased in a dose-dependent manner with phytase supplementation. Supplementation with 900 FTU/kg of phytase is recommended to improve the number of eggs produced per hen-housed and the number of marketable eggs produced through 23 to 72 wk of age, under this dietary setting.

How animal milk and plant-based alternatives diverge in terms of fatty acid, amino acid, and mineral composition

The decline in fresh milk in the Western world has in part been substituted by an increased consumption of plant-based beverages (PBB). These are often marketed as healthy and sustainable alternatives to milk and dairy foodstuff, although studies have suggested PBB to be of lower nutrient quality. The current study considered different brands of almond-, oat-, rice-, coconut- and soya-based beverages for a comparative analysis and found that they indeed presented lower contents of total protein, lipids, amino acids, and minerals than cow and goat milk. The only exception was given by soya-based beverages which approximated the protein content (3.47% vs. 3.42 and 3.25% in cow and goat milk, respectively) and amino acid composition of animal milk, and also demonstrated high mineral content. The natural presence of phyto-compounds in PBB characterised as antinutrients and their potential to exacerbate the issue of low nutrient quality by lowering bioavailability have been discussed.

Two-sided effects of the organic phosphorus phytate on a globally important marine coccolithophorid phytoplankton

Dissolved organic phosphorus (DOP) is a potential source of aquatic eutrophication and pollution because it can potentially stimulate growth in some species and inhibit growth in other species of algae, the foundation of the marine ecosystem. Inositol hexaphosphate (also named phytic acid or PA), an abundant organophosphate, is presumably ubiquitous in the marine environment, but how it affects marine primary producers is poorly understood. Here, we investigated the bioavailability of this DOP to the cosmopolitan coccolithophore Emiliania huxleyi. Our results showed that E. huxleyi cells can take up PA and dissolved inorganic phosphorus (DIP) simultaneously. Absorbed PA can efficiently support algal growth, producing cell yield between DIP and phosphorus (P)-depleted conditions. Accordingly, PA supply as the sole P source highly influences cellular metabolism and nutrient stoichiometry. Particularly, PA-grown cultures exhibited enhanced carbon fixation, increased lipid content, activated energy metabolism, and induced nitrogen assimilation. However, our data suggest that PA may also exert some levels of toxic effects on E. huxleyi. This study provides novel insights into the variable effects of a DOP on marine phytoplankton, which will inform new inquiries about how the complex DOP constituencies in the ocean will shape phytoplankton community structure and function. IMPORTANCE The dissolved organic phosphorus (DOP) utilization in phytoplankton plays vital roles in cellular P homeostasis, P-nutrient niche, and the dynamics of community structure in marine ecosystems, but its mechanisms, potentially varying with species, are far from clear. In this study, we investigated the utilization of a widespread DOP species, which is commonly produced by plants (land plants and marine macrophytes) and released into coastal areas, in a globally distributed bloom-forming coccolithophore species in various phosphorus environments. Using a combination of physiological and transcriptomic measurements and analyses, our experimental results revealed the complex mechanism and two-sided effects of DOP (major algal growth-supporting and minor toxic effects) in this species, providing a novel perspective on phytoplankton nutrient regulation.

Origin, Diversity, and Multiple Roles of Enzymes with Metallo-β-Lactamase Fold from Different Organisms

β-lactamase enzymes have generated significant interest due to their ability to confer resistance to the most commonly used family of antibiotics in human medicine. Among these enzymes, the class B β-lactamases are members of a superfamily of metallo-β-lactamase (MβL) fold proteins which are characterised by conserved motifs (i.e., HxHxDH) and are not only limited to bacteria. Indeed, as the result of several barriers, including low sequence similarity, default protein annotation, or untested enzymatic activity, MβL fold proteins have long been unexplored in other organisms. However, thanks to search approaches which are more sensitive compared to classical Blast analysis, such as the use of common ancestors to identify distant homologous sequences, we are now able to highlight their presence in different organisms including Bacteria, Archaea, Nanoarchaeota, Asgard, Humans, Giant viruses, and Candidate Phyla Radiation (CPR). These MβL fold proteins are multifunctional enzymes with diverse enzymatic or non-enzymatic activities of which, at least thirteen activities have been reported such as β-lactamase, ribonuclease, nuclease, glyoxalase, lactonase, phytase, ascorbic acid degradation, anti-cancer drug degradation, or membrane transport. In this review, we (i) discuss the existence of MβL fold enzymes in the different domains of life, (ii) present more suitable approaches to better investigating their homologous sequences in unsuspected sources, and (iii) report described MβL fold enzymes with demonstrated enzymatic or non-enzymatic activities.

Scenario analysis of phosphorus flow in food production and consumption system in the Mwanza region, Tanzania

Since the mineral, phosphorus (P), has dual properties of being limited resources for use, and being a pollutant for studying sustainable management of anthropogenic P flows in wetlands and soils, currently P receives the highest interests among researchers around the world. This study has successfully mapped P flows for a reference year (2017) and a future year (2030) using different scenarios of food production and consumption system (hereafter 'system') in the Mwanza region (Tanzania). The results showed that the total P input and output for 2017 alone were 9770 t and 7989 t, respectively. However, as high as 1781 tP accumulated in the system and the potentially recyclable P found, is yet to be recovered due to economic reasons and the lack of market. The main anthropogenic P input to the system occurred via imported feed, fertilizer, and crop food, accounting for about 99.72 % of the total input flow. The output was comprised of animal products exported with 3428 tP, and various P-contained wastes which were lost to water bodies with 4561tP. Analysis of the 2030 scenario showed that setting P management objectives from different perspectives such as the total P budget balance, potential recyclable P, and P emission, can help develop differentially preferred management strategies and measures in the Mwanza region. The combination of diet change, precision feeding, and integrated waste management practices presents the best prospects for decreasing P budget and losses, and the amount of P that can be potentially recovered from the system. We propose a package of integrated P management measures for the Mwanza region. Given the similarity of regional socio-economic development background around the Lake Victoria basin, the model can be used to guide the study of anthropogenic P flow analysis in other areas along the shore of Lake Victoria (Africa).

In vitro assessment for the probiotic potential of Pichia kudriavzevii

It is of interest to isolate the probiotic yeast Pichia kudriavzevii based on its probiotic characteristics and enzyme production. The isolate was able to withstand high acid, bile concentration and showed a high viability. Additionally, it showed auto aggregation ability that increases with time and hydrophobicity with xylene. It was resistant to different antibiotics and showed no hemolytic activity. The isolate was also capable of producing phytase that can break down phytate. Overall, the characteristics of P. kudriavzevii suggest that it could potentially have probiotic properties, and its ability to produce phytase could also make it useful in feed and animal industries.

Nutritional Strategies to Improve Meat Quality and Composition in the Challenging Conditions of Broiler Production: A Review

Poultry meat is becoming one of the most important animal protein sources for human beings in terms of health benefits, cost, and production efficiency. Effective genetic selection and nutritional programs have dramatically increased meat yield and broiler production efficiency. However, modern practices in broiler production result in unfavorable meat quality and body composition due to a diverse range of challenging conditions, including bacterial and parasitic infection, heat stress, and the consumption of mycotoxin and oxidized oils. Numerous studies have demonstrated that appropriate nutritional interventions have improved the meat quality and body composition of broiler chickens. Modulating nutritional composition [e.g., energy and crude protein (CP) levels] and amino acids (AA) levels has altered the meat quality and body composition of broiler chickens. The supplementation of bioactive compounds, such as vitamins, probiotics, prebiotics, exogenous enzymes, plant polyphenol compounds, and organic acids, has improved meat quality and changed the body composition of broiler chickens.

Dietary fumonisin may compromise the nutritive value of feed and distort copper and zinc digestibility and retention in weaned piglets

Fumonisins (FUM) have been reported to impede gut functioning in pigs. However, investigations into the possible effect on mineral metabolism are limited. Thus, the trial studied the apparent total tract digestibility (ATTD) and retention of dietary nitrogen and minerals, intestinal architecture, digestive enzymes activity and heat-shock protein 70 (Hsp70) activity. Eighteen weaned piglets of 7 weeks old were assigned to three groups and their feed either contained 0, 15 or 30 mg FUM/kg for 21 days. ATTD and retention of dietary N and minerals were measured in a 5- day long balance trial between Day 17 and Day 21. The digestible and metabolisable energy (DE and ME) content of the feeds were also determined. The body weights, cumulative feed intake, relative organ weights, digestive enzymes activity and intestinal morphology were not affected (p > 0.05) by dietary treatments. The DE content was significantly lower (p < 0.05) when the feed contained 15 mg/kg FUM, but no statistically reliable treatment effect was confirmed for ME content. Dietary FUM significantly lowered (p < 0.05) the ATTD of Ca and P but not (p > 0.05) N, K, Mg and Na. The relative retention rate of N, Ca, P, K, Mg and Na in all groups were not impacted (p > 0.05) by treatments. The ATTD and relative retention of Cu and Zn were remarkably (p < 0.05) lower in piglets fed FUM-contaminated feed. In addition, the expression of Hsp70 activity in the liver was significantly elevated (p < 0.05) in the highest treatment group. These findings suggest that a dietary dose of 15 or 30 mg FUM/kg diet distorts the nutritive value of the mixed feed, results in poor ATTD and retention rates of Zn and Cu, and elevate Hsp70 activity in the liver without altering intestinal architecture or digestive enzymes' activity in weaned piglets.

A meta-analysis of the effects of clay mineral supplementation on alkaline phosphatase, broiler health, and performance

The crucial constraint in the broiler production sector is feed efficiency; many feed additives have been widely employed to increase broiler growth. Nonetheless, some of these substances exacerbate health and animal-based food product safety concerns. This meta-analysis examines the effect of clay minerals on alkaline phosphatase (ALP), broiler health, and performance. Metadata was constructed from 369 data items that were harvested from 86 studies. The addition of clay minerals was set as a fixed effect and the difference between experiments was established as a random effect. The metadata were fitted using a linear mixed model. Due to the presence of clay minerals, growth performance as assessed by body weight (BW), average daily gain (ADG), and performance efficiency index (PEI) increased significantly (P < 0.01). In the total period, the increases of BW, ADG, and PEI were 4.12 g, 0.0714 g/d, and 0.648, respectively, per unit of clay minerals added. Clay minerals did not affect blood serum parameters (e.g., ALP and calcium). The IgA and IgM concentrations in the jejunum and ileum were significantly greater (P < 0.01) in the starter phase. Among clay minerals, broilers fed diets with aluminosilicate, halloysite, kaolin, and zeolite consistently exhibited higher (P < 0.05) BW, ADG, PEI, and lower feed conversion ratio (P < 0.05) in the finisher phase. Aluminosilicate was the only clay that increased (P < 0.05) secretory IgA concentration in both jejunum and ileum. In conclusion, clay minerals could be used as a growth promoter, especially during the finisher phase, without adversely affecting feed intake, liver function, and mineral metabolism in broiler chickens. Aluminosilicate was superior in improving the mucosal immunity status of broiler chickens.

Effects of Various Feed Additives on Finishing Pig Growth Performance and Carcass Characteristics: A Review

Feed additives have shown benefits throughout the literature in improving grow−finish pigs’ growth performance and carcass characteristics. However, the results have not been well summarized. Therefore, this review summarizes the available research (402 articles) on 14 feed additive categories fed to grow−finish pigs. The categories were acidifiers, betaine, Cr, conjugated linoleic acids, Cu, direct-fed microbials, carbohydrases, proteases, phytases, multi-enzymes, essential oils, L-carnitine, yeasts, and Zn. Qualified articles were collected and selected based on inclusion and exclusion criteria from online databases. The percentage difference for each response variable between the treatment and control group was calculated and summarized. Most results were positive for each feed additive; however, the magnitude of improvement varied, and most were not statistically significant. For ADG, DFM, Cu, L-carnitine, and multi-enzymes showed relatively large positive effects (>2.1% improvement) across a reasonable number of articles. Acidifiers, betaine, CLA, multi-enzymes, DFM, L-carnitine, and yeasts showed relatively large positive effects (>2.5% improvement) on improving G:F. Moreover, except for betaine, Cr, CLA, and L-carnitine, most feed additives showed little and non-significant effects on BF thickness (<1.7% improvement). This review provides a descriptive analysis for commonly used feed additives in the hope of better understanding feed additives’ effects on grow−finish pigs.

Effect of a biosynthetic bacterial 6-phytase on the digestibility of phosphorus and phytate in midlactating dairy cows

The effect of a biosynthetic bacterial 6-phytase (PhyG) on the digestibility and excretion of crude protein (CP), phosphorus (P), and phytate-P (PP) in midlactating dairy cows was investigated. Thirty Holstein-Friesians were assigned to three treatments with 10 cows per treatment in a randomized block design. Cows were fed forage (grass and corn silage) provided ad libitum, and a concentrate (without added inorganic phosphate) administered separately in amounts individualized per cow according to milk production, supplemented with phytase according to treatment. The formulated forage-to-concentrate-ratio was ~65%:35%. Dietary treatments comprised the control diet (CON) and CON supplemented with 2,000 (PhyG2,000) or 5,000 (PhyG5,000) phytase units (FTU)/kg DM in the total diet. The experiment comprised an 18-d preperiod for the collection of data to facilitate the allocation of cows to the treatments, followed by a 19-d experimental period comprising a 14-d diet adaptation period and 5 d of twice daily feces collection. Fecal samples were analyzed for the determination of apparent total tract digestibility (ATTD) of chemical constituents in the diet. The ATTD of PP was 92.6% in CON suggesting a high but incomplete degradation of phytate by ruminal microbial phytases. Cows fed PhyG2,000 exhibited increased ATTD of CP and PP [68.4% (2.7% points above CON) and 95.1% (2.5% points above CON), respectively] whilst PhyG5,000 further increased ATTD PP and also increased ATTD P [54.1% (7.8% points above CON)]; ATTD of Ca tended to be increased in PhyG5,000 vs. CON. Linear dose-response relationships were observed for ATTD of DM, CP, P, Ca, and PP. In addition, fecal excretion of P, and PP linearly reduced and that of Ca and CP tended to linearly reduce with increasing PhyG dose level. No difference was observed for DM intake and milk composition was unaffected except for milk protein which tended to be higher in cows fed PhyG5,000 than CON. In summary, the addition of exogenous phytase at 2,000 FTU/kg or higher to diets of lactating dairy cows improved P, PP, Ca, and CP digestibility and reduced fecal excretion of P, PP, and CP in a dose-dependent manner.

Evaluating a novel consensus bacterial 6-phytase variant on growth performance of broilers fed U.S. commercial diets deficient in nutrients and energy through 63 days of age

An experiment was conducted to evaluate the efficacy of a novel consensus bacterial 6-phytase variant expressed in Trichoderma reesei (PhyG) in broilers fed corn-soybean meal-based diets with application of dose-specific full nutrient and energy matrix values. Ross 708, straight-run broilers (n = 2,016) were assigned to one of 7 dietary treatments, with 12 replicate pens/diet and 24 birds/pen. Diets were a nutrient adequate control (PC), nutrient reduced negative controls 1, 2, and 3 (NC1, NC2, and NC3) with reductions in available phosphorus (avP) by 0.15%, 0.18%, and 0.19%, calcium (Ca) by 0.17%, 0.20%, and 0.21%, dig amino acids (AA) by 0.02%-0.05%, sodium (Na) by 0.03%-0.05%, and metabolizable energy (ME) by 62.8, 68.8, and 69.5 kcal/kg, respectively. Other diets were the NC1, NC2, and NC3 respectively supplemented with 500 (PhyG500), 1,000 (PhyG1000), and 2,000 (PhyG2000) FTU/kg. Over the 63-day feeding period, decreasing nutrient specifications lowered body weights (P < 0.05) in broilers from 4,518 g in PC to 4,256 g and 4,191 g and increased body weight-corrected feed conversion ratio (FCR, P < 0.05) from 1.92 in PC to 2.06 and 2.08 in the NC2 and NC3, respectively. Compared with PC, PhyG maintained (P > 0.05) BW in broilers fed PhyG500 (4,474 g), PhyG1000 (4,417 g), and PhyG2000 (4,449 g). Moreover, PhyG at all dose-levels maintained (P > 0.05) overall FCR vs. PC. The NC1, NC2, and NC3 diets decreased (P < 0.05) tibia ash vs. PC, and each PhyG500, PhyG1000, and PhyG2000 completely restored tibia ash to the similar levels (P > 0.05) as the PC. Carcass yield was decreased (P < 0.05) by NC1 (80.63%), NC2 (80.51%), and NC3 (80.31%) vs. PC (81.96%) with complete alleviation by PhyG500 (82.11%), PhyG1000 (81.80%), and PhyG2000 (81.54%). In conclusion, the novel consensus phytase variant completely compensated for the reduction in dietary avP, Ca, dig AA, and ME at each dose-level and maintained growth performance, bone quality, carcass characteristics, and nutrient digestibility in a typical corn-soybean mean based diet fed to broilers through 63 days of age.

The effect of bone and analytical methods on the assessment of bone mineralization response to dietary phosphorus, phytase, and vitamin D in nursery pigs

A total of 360 pigs (DNA 600 × 241, DNA; initially 11.9 ± 0.56 kg) were used in a 28-d trial to evaluate the effects of different bones and analytical methods on the assessment of bone mineralization response to dietary P, vitamin D, and phytase in nursery pigs. Pens of pigs (six pigs per pen) were randomized to six dietary treatments in a randomized complete block design with 10 pens per treatment. Dietary treatments were designed to create differences in bone mineralization and included: (1) 0.19% standardized total tract digestibility (STTD) P (deficient), (2) 0.33% STTD P (NRC [2012] requirement) using monocalcium phosphate, (3) 0.33% STTD P including 0.14% release from phytase (Ronozyme HiPhos 2700, DSM Nutritional Products, Parsippany, NJ), (4) 0.44% STTD P using monocalcium phosphate, phytase, and no vitamin D, (5) diet 4 with vitamin D (1,653 IU/kg), and (6) diet 5 with an additional 50 µg/kg of 25(OH)D3 (HyD, DSM Nutritional Products, Parsippany, NJ) estimated to provide an additional 2,000 IU/kg of vitamin D3. After 28 d on feed, eight pigs per treatment were euthanized for bone (metacarpal, 2nd rib, 10th rib, and fibula), blood, and urine analysis. The response to treatment for bone density and ash was dependent upon the bone analyzed (treatment × bone interaction for bone density, P = 0.044; non-defatted bone ash, P = 0.060; defatted bone ash, P = 0.068). Thus, the response related to dietary treatment differed depending on which bone (metacarpal, fibula, 2nd rib, or 10th rib) was measured. Pigs fed 0.19% STTD P had decreased (P < 0.05) bone density and ash (non-defatted and defatted) for all bones compared to 0.44% STTD P, with 0.33% STTD P generally intermediate or similar to 0.44% STTD P. Pigs fed 0.44% STTD P with no vitamin D had greater (P < 0.05) non-defatted fibula ash compared to all treatments other than 0.44% STTD P with added 25(OH)D3. Pigs fed diets with 0.44% STTD P had greater (P < 0.05) defatted second rib ash compared to pigs fed 0.19% STTD P or 0.33% STTD P with no phytase. In summary, bone density and ash responses varied depending on bone analyzed. Differences in bone density and ash in response to P and vitamin D were most apparent with fibulas and second ribs. There were apparent differences in the bone ash percentage between defatted and non-defatted bone. However, differences between the treatments remain consistent regardless of the analytic procedure. For histopathology, 10th ribs were more sensitive than 2nd ribs or fibulas for the detection of lesions.

Evaluation of a novel phytase derived from Citrobacter braakii and expressed in Aspergillis oryzae on growth performance and bone mineralization indicators in nursery pigs

A total of 297 pigs (DNA 241 × 600; initially 8.64 ± 0.181 kg) were used in a 21-d trial to determine the efficacy of a novel phytase derived from Citrobacter braakii and expressed in Aspergillis oryzae (HiPhorius; DSM Nutritional Products, Animal Nutrition & Health, Parsippany, NJ) on pig growth and bone mineralization indicators. Pens of pigs were assigned to 1 of 5 dietary treatments in a randomized complete block design with 5 pigs per pen and 12 pens per treatment. The trial was initiated 14-d after weaning. The first three treatments were formulated to contain 0.09% aP; without added phytase (control), or the control diet with 600 or 1,000 FYT/kg of added phytase (considering a release of 0.15% or 0.18% aP, respectively). The remaining two treatments were formulated to contain 0.27% aP, one without added phytase and the other with 1,000 FYT/kg. From days 0 to 21, pigs fed increasing phytase in diets containing 0.09% aP had increased (linear, P ≤ 0.002) ADG, ADFI, and G:F, but added phytase in the 0.27% aP diet did not impact growth performance. Increasing phytase in diets containing 0.09% aP increased percentage bone ash in metacarpals and 10th ribs (linear, P < 0.001; quadratic, P = 0.004, respectively), and increased grams of Ca and P in metacarpals, 10th ribs, and fibulas (linear, P ≤ 0.027). Adding 1,000 FYT/kg phytase in diets with 0.27% aP increased (P ≤ 0.05) percentage bone ash and grams of Ca and P in fibulas and 10th ribs compared with pigs fed 0.27% aP without added phytase. Increasing aP from 0.09% to 0.27% in diets without added phytase increased (P < 0.001) ADG, ADFI, and G:F. Increasing aP from 0.09% to 0.27% in diets without added phytase increased bone density (P ≤ 0.002) in fibulas and metacarpals, percentage bone ash in all bones (P ≤ 0.074), and increased (P < 0.05) grams of Ca and P in fibulas and 10th ribs. Pigs fed diets containing 0.09 or 0.27% aP, both with 1,000 FYT added phytase, had increased (P < 0.05) bone density in fibulas and metacarpals, percentage bone ash in all bones, and increased grams of Ca and P in fibulas and 10th ribs. For growth performance (average of ADG and G:F), aP release was calculated to be 0.170% for 600 FYT/kg and 0.206% for 1,000 FYT/kg. For the average of all bone measurements (average of 3 bones for both bone density and percentage bone ash), aP release was calculated to be 0.120% and 0.125% for 600 and 1,000 FYT/kg, respectively.

Phylogenetic analysis, computer modeling and catalytic prediction of an Amazonian soil β-glucosidase against a soybean saponin

Saponins are amphipathic glycosides with detergent properties present in vegetables. These compounds, when ingested, can cause difficulties in absorbing nutrients from food and even induce inflammatory processes in the intestine. There is already some evidence that saponins can be degraded by β-glucosidases of the GH3 family. In the present study, we evaluated, through computational tools, the possibility of a β-glucosidase (AMBGL17) obtained from a metagenomic analysis of the Amazonian soil, to catalytically interact with a saponin present in soybean. For this, the amino acid sequence of AMBGL17 was used in a phylogenetic analysis to estimate its origin and to determine its three-dimensional structure. The 3D structure of the enzyme was used in a molecular docking analysis to evaluate its interaction with soy saponin as a ligand. The results of the phylogenetic analysis showed that AMBGL17 comes from a microorganism of the phylum Chloroflexi, probably related to species of the order Aggregatinales. Molecular docking showed that soybean saponin can interact with the catalytic site of AMBGL17, with the amino acid GLY345 being important in this catalytic interaction, especially with a β-1,2 glycosidic bond present in the carbohydrate portion of saponin. In conclusion, AMBGL17 is an enzyme with interesting biotechnological potential in terms of mitigating the anti-nutritional and pro-inflammatory effects of saponins present in vegetables used for human and animal food.

Nutritional and Functional Roles of Phytase and Xylanase Enhancing the Intestinal Health and Growth of Nursery Pigs and Broiler Chickens

This review paper discussed the nutritional and functional roles of phytase and xylanase enhancing the intestinal and growth of nursery pigs and broiler chickens. There are different feed enzymes that are currently supplemented to feeds for nursery pigs and broiler chickens. Phytase and xylanase have been extensively studied showing consistent results especially related to enhancement of nutrient digestibility and growth performance of nursery pigs and broiler chickens. Findings from recent studies raise the hypothesis that phytase and xylanase could play functional roles beyond increasing nutrient digestibility, but also enhancing the intestinal health and positively modulating the intestinal microbiota of nursery pigs and broiler chickens. In conclusion, the supplementation of phytase and xylanase for nursery pigs and broiler chickens reaffirmed the benefits related to enhancement of nutrient digestibility and growth performance, whilst also playing functional roles benefiting the intestinal microbiota and reducing the intestinal oxidative damages. As a result, it could contribute to a reduction in the feed costs by allowing the use of a wider range of feedstuffs without compromising the optimal performance of the animals, as well as the environmental concerns associated with a poor hydrolysis of antinutritional factors present in the diets for swine and poultry.

Broiler physiological response to low phosphorus diets at different stages of production

Phosphorus (P) inclusion in broiler diets needs to meet the physiological demands at a specific developmental stage to ensure the performance, health, and welfare of the birds and minimize nutrient losses. Toward a more efficient utilization of P in broiler husbandry, a timed nutritional conditioning strategy might enhance the endogenous mechanisms of mineral homeostasis and thus reduce dietary P supply of mineral sources. In this study, following a variable P supply in the starter phase, the effects of a dietary P depletion of broiler chickens were investigated at different developmental stages. Physiological adaptation mechanisms were elucidated based on zootechnical performance, endocrine parameters, regulation of intestinal P transport, bone characteristics, and health aspects. The results revealed a marked response to P depletion at the earliest developmental phase, after which indications of effective compensatory mechanism were detectable with advancing ages. Potential mechanisms that enable broilers to maintain mineral homeostasis primarily include endocrine control mediated by calcitriol actions, as well as intestinal P uptake and mineral mobilization from the bone. Conclusively, the precise timing, duration, and extent of a P depletion strategy in the broiler chicken might be considered for optimized nutrient utilization.

Potential Probiotics Role in Excluding Antibiotic Resistance

Background. Antibiotic supplementation in feed has been continued for the previous 60 years as therapeutic use. They can improve the growth performance and feed efficiency in the chicken flock. A favorable production scenario could favor intestinal microbiota interacting with antibiotic growth promoters and alter the gut bacterial composition. Antibiotic growth promoters did not show any beneficial effect on intestinal microbes. Scope and Approach. Suitable and direct influence of growth promoters are owed to antimicrobial activities that reduce the conflict between host and intestinal microbes. Unnecessary use of antibiotics leads to resistance in microbes, and moreover, the genes can relocate to microbes including Campylobacter and Salmonella, resulting in a great risk of food poisoning. Key Findings and Conclusions. This is a reason to find alternative dietary supplements that can facilitate production, growth performance, favorable pH, and modulate gut microbial function. Therefore, this review focus on different nutritional components and immune genes used in the poultry industry to replace antibiotics, their influence on the intestinal microbiota, and how to facilitate intestinal immunity to overcome antibiotic resistance in chicken.

Does supplementing β-mannanase modulate the feed-induced immune response and gastrointestinal ecology in poultry and pigs? An appraisal

The provision of adequate and balanced nutrients is critical for efficient and profitable animal protein production. However, non-nutritive components in feedstuffs can elicit responses that can negatively impact nutrient utilization efficiency. For example, dietary β-mannans are recognizable by cell surface mannose receptors are pivotal for diverse cellular functions. This review will evaluate the physiological implications of dietary native β-mannans, the utility of supplemental feed β-mannanase in hydrolyzing β-mannans, and subsequent metabolic responses. Dietary native β-mannans have been implicated in inadvertent stimulation of immune response through a phenomenon called the feed-induced immune response (FIIR), that has been associated with intestinal inflammation and depression in animal performance. Supplemental β-mannanase blunted the FIIR by hydrolyzing native β-mannans to smaller fragments with a reduced ability to stimulate the innate immune system as indicated by the modulation of oxidative stress, mucosal permeability, and blood concentration of acute phase proteins and immunoglobulins in broilers and piglet models. Moreover, β-mannanase hydrolysis of native β-mannans to mannooligosaccharides (MOS) impacted gastrointestinal microbial ecology. Indeed, β-mannanase-derived MOS reduced the concentration of pathogenic bacteria such as Escherichia coli and Salmonella and increased the production of short-chain fatty acids in gastrointestinal tracts of various animal models. Consequently, by hydrolyzing native β-mannans, supplemental β-mannanase may have nutritional, metabolic, and microbial ecology benefits. In summary, integrating multi-functional feed additives such as β-mannanase into feeding programs for monogastric animals will be critical for efficient and sustainable animal protein production in the context of evolving challenges such as the mandated elimination of use of antibiotics for growth promotion.

Calcium chloride is a better calcium source rather than calcium carbonate for weanling pigs

Two experiments were conducted to evaluate the effects of calcium (Ca) levels in weanling pigs (Landrace × Yorkshire × Duroc). In experiment 1, one hundred and eighty weanling pigs were randomly allotted to one of the three treatments. The treatments were low (Ca 0.60% in phase 1 and 0.50% in phase 2), standard (Ca 0.72% in phase 1 and 0.66% in phase 2), and high (Ca 0.84% in phase 1 and 0.72% in phase 2). In experiment 2, hundred and forty weanling pigs were randomly assigned to one of four treatments differing in Ca levels (high and low) and sources (CaCl2 and CaCO3) in a 2 × 2 factorial arrangement. There were 10 pigs per replicate in both experiments, with 6 replicates in each treatment, and they were conducted in two phases (phase 1, days 0-14; phase 2, days 15-28). In experiment 1, body weight (BW), average daily gain (ADG), and growth to feed ratio (G/F) increased as the Ca level decreased (p < 0.05). P digestibility was higher in the low-Ca diet group than in the high-Ca diet group (p <0.05). In experiment 2, the final BW, ADG, and G/F increased in the CaCl2 diet group compared with the case in the CaCO3 diet group (p < 0.05). The digestibility of crude protein (CP), Ca, and P was higher in the CaCl2 diet group than in the CaCO3 diet group (p < 0.05). Cl- levels were higher in the CaCl2 diet group than in the CaCO3 diet group (p < 0.05). The bicarbonate (HCO3 -), base excess (BE), and electrolyte balance (EB) levels were lower in the CaCl2 diet group than in the CaCO3 diet group (p < 0.05). Hematocrit increased as the Ca level decreased (p < 0.05). The HCO3 - interacted with the Ca sources and thus, affected the Ca levels (p < 0.05). Bone ash, Ca, and P were downregulated in the low-Ca diet group compared with the case in the high-Ca diet group. Overall, the low dietary Ca supplementation led to greater growth performance. Furthermore, CaCl2 appeared to be a better Ca source than CaCO3 because of the greater digestibility of CP, Ca, and P, and improved EB.

Mucosal expression of Ca and P transporters and claudins in the small intestine of broilers is altered by dietary Ca:P in a limestone particle size dependent manner

High calcium (Ca) intake and fine limestone reduces precaecal phosphorus (P) absorption independently of P solubility in broilers. This study aimed to determine whether dietary total Ca: total P ratio (Ca:P) and limestone particle size (LPS) affect gene expression of P transporters in the small intestine. A total of 384 one-day-old Ross 308 male broiler chickens received diets low (0.50), medium (1.00) or high (1.75) in Ca:P containing either fine (160 μm) or coarse (1062 μm) limestone, in a 3×2 factorial arrangement. Expression of Ca- and P-related genes were determined using real-time quantitative PCR (RT-qPCR) in duodenum and jejunum. Increasing dietary Ca:P decreased duodenal calcium-sensing receptor (CaSR), calbindin-D28k (CaBP-D28k), plasma membrane Ca-ATPase 1 (PMCA1) and sodium-coupled P cotransporter type IIb (NaPi-IIb), but not transient receptor potential canonical 1 (TRPC1) mRNA. This effect was greater with fine limestone when Ca:P increased from low to medium, but greater with coarse limestone when increased from medium to high. A similar inhibitory effect was observed for jejunal CaBP-D28k expression where increasing dietary Ca:P and fine limestone decreased CaSR mRNA, while dietary Ca:P decreased TRPC1 mRNA only for coarse limestone. It also decreased jejunal NaPi-IIb mRNA irrespective of LPS. Dietary treatments did not affect jejunal PMCA1 mRNA expression or that of inorganic phosphate transporter 1 and 2 and xenotropic and polytropic retrovirus receptor 1 in both intestinal segments. Dietary Ca increase reduced mucosal claudin-2 mRNA in both segments, and jejunal zonula occludens-1 (ZO-1) mRNA only for coarse limestone. In conclusion, increasing dietary Ca:P reduced expression of duodenal P transporters (NaPi-IIb) in a LPS dependent manner, hence Ca induced reduction in intestinal P absorption is mediated by decreasing P transporters expression. Dietary Ca reduces Ca digestibility by downregulating mRNA expression of both Ca permeable claudin-2 and Ca transporters (CaBP-D28k, PMCA1).

Characterisation of a soil MINPP phytase with remarkable long-term stability and activity from Acinetobacter sp

Phylogenetic analysis, homology modelling and biochemical methods have been employed to characterize a phytase from a Gram-negative soil bacterium. Acinetobacter sp. AC1-2 phytase belongs to clade 2 of the histidine (acid) phytases, to the Multiple Inositol Polyphosphate Phosphatase (MINPP) subclass. The enzyme was extraordinarily stable in solution both at room temperature and 4°C, retaining near 100% activity over 755 days. It showed a broad pH activity profile from 2–8.5 with maxima at 3, 4.5–5 and 6. The enzyme showed Michaelis-Menten kinetics and substrate inhibition (Vmax, Km, and Ki, 228 U/mg, 0.65 mM and 2.23 mM, respectively). Homology modelling using the crystal structure of a homologous MINPP from a human gut commensal bacterium indicated the presence of a potentially stabilising polypeptide loop (a U-loop) straddling the active site. By employ of the enantiospecificity of Arabidopsis inositol tris/tetrakisphosphate kinase 1 for inositol pentakisphosphates, we show AC1-2 MINPP to possess D6-phytase activity, which allowed modelling of active site specificity pockets for InsP6 substrate. While phytase gene transcription was unaltered in rich media, it was repressed in minimal media with phytic acid and orthophosphate as phosphate sources. The results of this study reveal AC1-2 MINPP to possess desirable attributes relevant to biotechnological use.