Phytases from Enterobacter and Serratia species with desirable characteristics for food and feed applications

Exploring the biotechnological potential of novel soil-derived Klebsiella sp. and Chryseobacterium sp. strains using phytate as sole carbon source

Phosphorus (P) is essential for biological systems, playing a pivotal role in energy metabolism and forming crucial structural components of DNA and RNA. Yet its bioavailable forms are scarce. Phytate, a major form of stored phosphorus in cereals and soils, is poorly bioavailable due to its complex structure. Phytases, enzymes that hydrolyze phytate to release useable phosphorus, are vital in overcoming this limitation and have significant biotechnological applications. This study employed novel method to isolate and characterize bacterial strains capable of metabolizing phytate as the sole carbon and phosphorus source from the Andes mountains soils. Ten strains from the genera Klebsiella and Chryseobacterium were isolated, with Chryseobacterium sp. CP-77 and Klebsiella pneumoniae CP-84 showing specific activities of 3.5 ± 0.4 nkat/mg and 40.8 ± 5 nkat/mg, respectively. Genomic sequencing revealed significant genetic diversity, suggesting CP-77 may represent a novel Chryseobacterium species. A fosmid library screening identified several phytase genes, including a 3-phytase in CP-77 and a glucose 1-phosphatase and 3-phytase in CP-84. Phylogenetic analysis confirmed the novelty of these enzymes. These findings highlight the potential of phytase-producing bacteria in sustainable agriculture by enhancing phosphorus bioavailability, reducing reliance on synthetic fertilizers, and contributing to environmental management. This study expands our biotechnological toolkit for microbial phosphorus management and underscores the importance of exploring poorly characterized environments for novel microbial functions. The integration of direct cultivation with metagenomic screening offers robust approaches for discovering microbial biocatalysts, promoting sustainable agricultural practices, and advancing environmental conservation.

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.

Production of fungal phytases in solid state fermentation and potential biotechnological applications

Phytases are important enzymes used for eliminating the anti-nutritional properties of phytic acid in food and feed ingredients. Phytic acid is major form of organic phosphorus stored during seed setting. Monogastric animals cannot utilize this phytate-phosphorus due to lack of necessary enzymes. Therefore, phytic acid excretion is responsible for mineral deficiency and phosphorus pollution. Phytases have been reported from diverse microorganisms, however, fungal phytases are preferred due to their unique properties. Aspergillus species are the predominant producers of phytases and have been explored widely as compared to other fungi. Solid-state fermentation has been studied as an economical process for the production of phytases to utilize various agro-industrial residues. Mixed substrate fermentation has also been reported for the production of phytases. Physical and chemical parameters including pH, temperature, and concentrations of media components have significantly affected the production of phytases in solid state fermentation. Fungi produced high levels of phytases in solid state fermentation utilizing economical substrates. Optimization of culture conditions using different approaches has significantly improved the production of phytases. Fungal phytases are histidine acid phosphatases exhibiting broad substrate specificity, are relatively thermostable and protease-resistant. These phytases have been found effective in dephytinization of food and feed samples with concomitant liberation of minerals, sugars and soluble proteins. Additionally, they have improved the growth of plants by increasing the availability of phosphorus and other minerals. Furthermore, phytases from fungi have played an important roles in bread making, semi-synthesis of peroxidase, biofuel production, production of myo-inositol phosphates and management of environmental pollution. This review article describes the production of fungal phytases in solid state fermentation and their biotechnological applications.

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.

Pectinases as promising green biocatalysts having broad-spectrum applications: Recent trends, scope, and relevance

Pectinases are a collection of multiple enzymes that have a common substrate, that is, pectin. They can act on different parts of pectin due to the structural heterogeneity of pectin. Therefore, they have been placed in different groups, such as protopectinases, polygalacturonases, polymethylesterases, pectin lyases, and pectate lyases. They are naturally present both in multicellular organisms such as higher plants and in unicellular organisms such as microbes. In past decade, it has been witnessed that chemical and mechanical methods employed in industrial processes have led to environmental hazards and serious health disorders, thus increasing the search for eco-friendly approaches with minimal health risks. Hence, microbial enzymes have been extensively used as safer alternative for these environmentally unsafe methods. Among these microbial enzymes, pectinases hold great significance and is one of the principal enzymes that have been used commercially. It is predominantly used as a green biocatalyst for fruit, fiber, oil, textile, beverage, pulp, and paper industry. Thus, this review focuses on the structure of pectin, microbial sources of pectin, and principle industrial applications of pectinases.

Phytase Mediated Beneficial Impact on Nutritional Quality of Biofortified Wheat Genotypes

Background:

Biofortification has been proposed as an intervention towards alleviation of micronutrient deficiency in the population of developing countries. However, the presence of anti- nutritional factor phytic acid in staple cereals chelates divalent cations and decreases their bioavailability for monogastric animals. Thus, the use of phytase enzyme for hydrolysing phytate-P and enhancing the amount of free divalent cations is of great importance.

Methods :

In this study, two phytases i.e. APF1 phytase from fungal source and commercial wheat phytase were supplemented with flours of biofortified wheat genotypes and their impact on food quality parameters was accessed. Since commercial wheat phytase is costly, it was used as known phytase to compare the application of APF1 phytase. The phytic acid content was reduced in the range of 70 to 84% with APF1 phytase and 79 to 89% with the wheat phytase as compared to untreated samples, respectively. In contrast to phytate, the dialyzability of important micronutrients Fe and Zn enhanced in the range of 21.9 to 48% and 39.5 to 96% with APF1 phytase and, 6.10 to 30% and 23.2 to 81% with wheat phytase, over untreated samples, respectively.

Results and Discussion:

A decrease in tannin content was observed in the range of 8 to 23% and 7 to 23% after treatment with APF1 and wheat phytase, respectively. The phytase treatment has resulted in increased soluble protein content and inorganic phosphate content to different level over untreated samples.

Conclusion:

The study revealed that APF1 phytase was comparatively more effective for enhanced nutritional quality of wheat flour through phytase supplementation for its food based applications.

Computational-based structural, functional and phylogenetic analysis of Enterobacter phytases

Myo-inositol hexakisphosphate phosphohydrolases (i.e., phytases) are known to be a very important enzyme responsible for solubilization of insoluble phosphates. In the present study, Enterobacter phytases have characterized by different phylogenetic, structural and functional parameters using some standard bio-computational tools. Results showed that majority of the Enterobacter phytases are acidic in nature as most of the isoelectric points were under 7.0. The aliphatic indices predicted for the selected proteins were below 40 indicating their thermostable nature. The average molecular weight of the proteins was 48 kDa. The lower values of GRAVY of the said proteins implied that they have better interactions with water. Secondary structure prediction revealed that alpha-helical content was highest among the other forms such as sheets, coils, etc. Moreover, the predicted 3D structure of Enterobacter phytases divulged that the proteins consisted of four monomeric polypeptide chains i.e., it was a tetrameric protein. The predicted tertiary model of E. aerogenes (A0A0M3HCJ2) was deposited in Protein Model Database (Acc. No.: PM0080561) for further utilization after a thorough quality check from QMEAN and SAVES server. Functional analysis supported their classification as histidine acid phosphatases. Besides, multiple sequence alignment revealed that "DG-DP-LG" was the most highly conserved residues within the Enterobacter phytases. Thus, the present study will be useful in selecting suitable phytase-producing microbe exclusively for using in the animal food industry as a food additive.

β-Propeller phytases: Diversity, catalytic attributes, current developments and potential biotechnological applications

Phytases are phosphatases which stepwise remove phosphates from phytic acid or its salts. β-Propeller phytase (BPPhy) belongs to a special class of microbial phytases that is regarded as most diverse, isolated and characterized from different microbes, mainly from Bacillus spp. BPPhy class is unique for its Ca²⁺-dependent catalytic activity, strict substrate specificity, active at neutral to alkaline pH and high thermostability. Numerous sequence and structure based studies have revealed unique attributes and catalytic properties of this class, as compared to other classes of phytases. Recent studies including cloning and expression and genetic engineering approaches have led to improvements in BPPhy which provide an opportunity for extended utilization of this class of phytases in improving animal nutrition, human health, plant growth promotion, and environmental protection, etc. This review describes the sources and diversity of BPPhy genes, biochemical properties, Ca²⁺ dependence, current developments in structural elucidation, heterogeneous expression and catalytic improvements, and multifarious applications of BPPhy.