Enhanced germination of barley (Hordeum vulgare L.) using chitooligosaccharide as an elicitor in seed priming to improve malt quality

The effect of L-cysteine on starch and protein degradation during barley germination

OBJECTIVES

In order to investigate the impact of L-cysteine (L-Cys) on starch and protein degradation during barley germination. The amylase activities, degradation of macromolecules during germination were determined in this study.

METHODS

Barley was germinated in petri dish for 0 to 5 days with different levels of L-Cys (0 mM, 2.5 mM, 5 mM, 10 mM).

RESULTS

L-Cys addition increased the total limit dextrinase (LD) activities and decreased the LD inhibitor activities during whole germination stage. The activities of α-amylase, β-amylase and free LD were increased with the addition of 2.5, 5 mM L-Cys at germination days 1 to 4. Due to higher amylase in malt with the addition of L-Cys, the non-fermentable sugars were reduced and the glucose, maltotriose were improved. Furthermore, the protein degradation analysis showed that low molecular weight protein increased and middle molecular weight protein decreased obviously in wort from the malt germinated with L-Cys, demonstrating that the L-Cys promote the protein degradation. Lastly, the filtration performance of malt with the addition of L-Cys during malting was better than the control.

CONCLUSION

In conclusion, L-Cys can promote the degradation of storage material (starch, protein) during barley germination, leading to a better green malt quality.

Chitosan oligosaccharide accelerates the dissemination of antibiotic resistance genes through promoting conjugative plasmid transfer

The dissemination of antibiotic resistance genes (ARGs), especially via plasmid-mediated horizontal gene transfer, poses a pervasive threat to global health. Chitosan-oligosaccharide (COS) is extensively utilized in medicine, plant and animal husbandry. However, their impact on microflora implies the potential to exert selective pressure on plasmid transfer. To explore the role of COS in facilitating the dissemination of ARGs via plasmid conjugation, we established in vitro mating models. The addition of COS to conjugation mixtures significantly enhanced the transfer of RP4 plasmid and mcr-1 positive IncX4 plasmid in both intra- and inter-specific. Phenotypic and transcriptome analysis revealed that COS enhanced intercellular contact by neutralizing cell surface charge and increasing cell surface hydrophobicity. Additionally, COS increased membrane permeability by inhibiting the Tol-Pal system, thereby facilitating plasmid conjugative transfer. Furthermore, COS served as the carbon source and was metabolized by E. coli, providing energy for plasmid conjugation through regulating the expression of ATPase and global repressor factor-related genes in RP4 plasmid. Overall, these findings improve our awareness of the potential risks associated with the presence of COS and the spread of bacterial antibiotic resistance, emphasizing the need to establish guidelines for the prudent use of COS and its discharge into the environment.

Chitosan-induced biotic stress tolerance and crosstalk with phytohormones, antioxidants, and other signalling molecules

Several polysaccharides augment plant growth and productivity and galvanise defence against pathogens. Such elicitors have ecological superiority over traditional growth regulators, considering their amplified biocompatibility, biodegradability, bioactivity, non-toxicity, ubiquity, and inexpensiveness. Chitosan is a chitin-derived polysaccharide that has recently been spotlighted among plant scientists. Chitosan supports plant growth and development and protects against microbial entities such as fungi, bacteria, viruses, nematodes, and insects. In this review, we discuss the current knowledge of chitosan's antimicrobial and insecticidal potential with recent updates. These effects are further explored with the possibilities of chitosan's active correspondence with phytohormones such as jasmonic acid (JA), salicylic acid (SA), indole acetic acid (IAA), abscisic acid (ABA), and gibberellic acid (GA). The stress-induced redox shift in cellular organelles could be substantiated by the intricate participation of chitosan with reactive oxygen species (ROS) and antioxidant metabolism, including hydrogen peroxide (H2O2), superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD). Furthermore, we propose how chitosan could be intertwined with cellular signalling through Ca2+, ROS, nitric oxide (NO), transcription factors (TFs), and defensive gene activation.

An overview of fungal chitinases and their potential applications

Chitin, the world's second most abundant biopolymer after cellulose, is composed of β-1,4-N-acetylglucosamine (GlcNAc) residues. It is the key structural component of many organisms, including crustaceans, mollusks, marine invertebrates, algae, fungi, insects, and nematodes. There has been a significant increase in the generation of chitinous waste from seafood businesses, resulting in a big amount of scrap. Although several organisms, such as plants, crustaceans, insects, nematodes, and animals, produce chitinases, microorganisms are promising candidates and a sustainable option that mediates chitin degradation. Fungi are the dominant group of chitinase producers among microorganisms. In fungi, chitinases are involved in morphogenesis, cell division, autolysis, chitin acquisition for nutritional purposes, and mycoparasitism. Many efficient chitinolytic fungi with potential applications have been identified in a variety of environments, including soil, water, marine wastes, and plants. The current review highlights the key sources of chitinolytic fungi and the characterization of fungal chitinases. It also discusses the applications of fungal chitinases and the cloning of fungal chitinase genes.

Whole genome sequencing of a novel chitinolytic Streptomyces sp. RB7AG reveals it's chitosan production potential: optimization of the process through Taguchi experimental design

This study reports about the De novo whole genome sequencing and analysis of a bacterial isolate Streptomyces sp. Strain. RB7AG, isolated from the sediments of Chilika Lake, Odisha, India. The genome report in this paper highlights a size of 7,708,681 bp and a GC content of 72.3%. It also consists of 7274 coding sequence, 66 tRNA and 4 rRNA. Furthermore, carbohydrate active enzyme analysis revealed that the strain RB7AG has 127 glycoside hydrolase family genes, which is well known for hydrolysis of glycosidic bond in complex sugars. Thus, exploiting these microorganisms for the production of chitosan can be an appropriate waste disposal method of choice. Chitosan being an important biomolecule that has various industrial applications. Hence, the study also sought to improve the culture conditions for the Streptomyces sp. strain RB7AG for generation, recovery, and characterization of chitosan. Utilizing the isolate, various low-cost nitrogen sources, including peptone, yeast extract, ammonium chloride, urea along with pH, media, metal ions and surfactant were assessed for chitosan synthesis. In this context, traditional methods such as One Factor One Time are more time consuming and expensive too. The current work aims to establish a methodology to optimize the degradation of chitin by the chitinolytic Streptomyces sp. strain RB7AG, isolated from lake sediment for the production of chitosan. More than one factor was considered at the time of experiments, and the knowledge was integrated into Taguchi statistical design to determine the contribution of the most important factors required to achieve the desired end product i.e. chitosan. Highest chitosan production (2.188 µg/ml) was observed in MSM media, 1.0% NaCl (w/v), 0.5% Yeast extract, 1% Ca2+ and 0.1% Tween 80 at pH 9. The whole genome analysis of RB7AG would help in determining the mechanism involved in the breakdown activity.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13205-023-03613-z.

Chitosan oligomers (COS) trigger a coordinated biochemical response of lemongrass (Cymbopogon flexuosus) plants to palliate salinity-induced oxidative stress

Plant susceptibility to salt depends on several factors from its genetic makeup to modifiable physiological and biochemical status. We used lemongrass (Cymbopogon flexuosus) plants as a relevant medicinal and aromatic cash crop to assess the potential benefits of chitosan oligomers (COS) on plant growth and essential oil productivity during salinity stress (160 and 240 mM NaCl). Five foliar sprays of 120 mg L^-1 of COS were applied weekly. Several aspects of photosynthesis, gas exchange, cellular defence, and essential oil productivity of lemongrass were traced. The obtained data indicated that 120 mg L^-1 COS alleviated photosynthetic constraints and raised the enzymatic antioxidant defence including superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD) activities that minimised salt-induced oxidative damage. Further, stomatal conductance (g_s) and photosynthetic CO₂ assimilation (A) were improved to support overall plant development. The same treatment increased geraniol dehydrogenase (GeDH) activity and lemongrass essential oil production. COS-induced salt resilience suggests that COS could become a useful biotechnological tool in reclaiming saline soil for improved crop productivity, especially when such soil is unfit for leading food crops. Considering its additional economic value in the essential oil industry, we propose COS-treated lemongrass as an excellent alternative crop for saline lands.

Chitinase-Assisted Bioconversion of Chitinous Waste for Development of Value-Added Chito-Oligosaccharides Products

Chito-oligosaccharides (COSs) are the partially hydrolyzed products of chitin, which is abundant in the shells of crustaceans, the cuticles of insects, and the cell walls of fungi. These oligosaccharides have received immense interest in the last few decades due to their highly promising bioactivities, such as their anti-microbial, anti-tumor, and anti-inflammatory properties. Regarding environmental concerns, COSs are obtained by enzymatic hydrolysis by chitinase under milder conditions compared to the typical chemical degradation. This review provides updated information about research on new chitinase derived from various sources, including bacteria, fungi, plants, and animals, employed for the efficient production of COSs. The route to industrialization of these chitinases and COS products is also described.

Inhibition of Chitosan with Different Molecular Weights on Barley-Borne Fusarium graminearum during Barley Malting Process for Improving Malt Quality

There are many Fusarium graminearum contaminations in barley that are often associated with malt and beer quality issues. Thus, it is important to find a biological antifungal agent to prevent the growth of F. graminearum during malting. Minimum inhibition concentration (MIC) of chitosan for mycelial growth and spore germination of F. graminearum was 2.6 g/L and 1.6 g/L, respectively, indicating that the F. graminearum strain was highly sensitive toward chitosan. Chitosan with a molecular weight of 102.7 kDa was added at 0.5 g/kg during the first steeping stage, resulting in the maximum inhibition rate of F. graminearm in barley. The biomass of F. graminearm and deoxynivalenol content in the infected barley at the end of germination with 0.5 g/kg chitosan treatment were decreased by 50.7% and 70.5%, respectively, when compared with the infected barley without chitosan. Chitosan could remove the negative effects of F. graminearm infection on barley germination and malt quality, which makes the application of chitosan during the steeping process as a potential antifungal agent in the malting process to protect from F. graminearum infection.

Wool Wax Extraction From Washing Effluent and Effect on Olea europea Germination and Growth

Effluents from textile industry using wool pose serious environmental nuisances in Tunisia that are mainly due to their pollutant load and the release of unpleasant odors. In order to minimize these hazards and to take advantage of these wastes for the sake of our environment, the present work consists on valuating wool wax from washing effluent on olive (Olea europea), germination and growth. Extraction was made in water at 70°C or hexane using sonication followed by concentration of the extracts in soxhlet apparatus. Results showed that this waste is characterized by its richness in total lipid content with extraction yields of 60.7 and 95.6%, respectively. GC-MS analysis of wax showed its richness on fatty acids. Six saturated fatty acids ranking from 15 to 27 carbon atoms were characterized. Furthermore, diluted wax at a dose of 1.25 mg/g significantly improves germination of olive seeds by germination index calculation, to reach a maximum of 150 ± 17%. In fertigation experiment, the use of the same dose of diluted wax promotes plant length to reach 45.7 ± 2.52 cm. GC-MS analysis after derivatization showed significant enhancement of auxin production in plants treated with 1.25 mg of wax/g of soil compared to control with a concentration of 1.1 ± .1 and .7 ± .2 ng/mg, respectively. This leads us to valuate wool wax as environmental friendly natural product in agricultural and fertigation practice of olive plant.

Exploration of genomic and functional features of chitinolytic bacterium Streptomyces chilikensis RC1830, isolated from Chilika Lake, India

Streptomyces chilikensis RC1830 was previously isolated as a novel chitinolytic streptomycete from Chilika Lake, Odisha, India. The strain RC1830 is a representative member of the soil-dwelling, filamentous Streptomyces group that produces the majority of natural antibiotics and secondary metabolites. The objective of this work was to assess the chitin degradation ability and whole-genome sequence of Streptomyces chilikensis RC1830. TLC analysis of the fermentation product revealed that strain RC1830 can convert shrimp shell colloidal chitin to N-acetylated chitooligosaccharides (N-AcCOS). A genome-wide investigation of RC1830 was also carried out to investigate the genetic basis for chitin breakdown. The result showed that the RC1830 genome possesses a chromosome with 7,121,774 bp (73.2% GC). The genome consists of 6807 coding sequences, 69 tRNA, and 3 rRNA genes. Furthermore, carbohydrate-active enzyme (CAZyme) analysis revealed that RC1830 has 89 glycoside hydrolase family genes, which could modulate the enzymes involved in the degradation of chitin ultimately producing industrially important COS. The whole-genome information of RC1830 could emphasize the mechanism involved in the RC1830's chitin breakdown activity, endowing RC1830 with a promising alternative for COS production.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13205-022-03184-5.

Enhancement of Vindoline and Catharanthine Accumulation, Antioxidant Enzymes Activities, and Gene Expression Levels in Catharanthus roseus Leaves by Chitooligosaccharides Elicitation

Catharanthus roseus (L.) G. Don is a plant belonging to the genus Catharanthus of the Apocynaceae family. It contains more than one hundred alkaloids, of which some exhibit significant pharmacological activities. Chitooligosaccharides are the only basic aminooligosaccharides with positively charged cations in nature, which can regulate plant growth and antioxidant properties. In this study, the leaves of Catharanthus roseus were sprayed with chitooligosaccharides of different molecular weights (1 kDa, 2 kDa, 3 kDa) and different concentrations (0.01 μg/mL, 0.1 μg/mL, 1 μg/mL and 10 μg/mL). The fresh weights of its root, stem and leaf were all improved after chitooligosaccharides treatments. More importantly, the chitooligosaccharides elicitor strongly stimulated the accumulation of vindoline and catharanthine in the leaves, especially with the treatment of 0.1 μg/mL 3 kDa chitooligosaccharides, the contents of them were increased by 60.68% and 141.54%, respectively. Furthermore, as the defensive responses, antioxidant enzymes activities (catalase, glutathione reductase, ascorbate peroxidase, peroxidase and superoxide dismutase) were enhanced under chitooligosaccharides treatments. To further elucidate the underlying mechanism, qRT-PCR was used to investigate the genes expression levels of secologanin synthase (SLS), strictosidine synthase (STR), strictosidine glucosidase (SGD), tabersonine 16-hydroxylase (T16H), desacetoxyvindoline-4-hydroxylase (D4H), deacetylvindoline-4-O-acetyltransferase (DAT), peroxidase 1 (PRX1) and octadecanoid-responsive Catharanthus AP2-domain protein 3 (ORCA3). All the genes were significantly up-regulated after chitooligosaccharides treatments, and the transcription abundance of ORCA3, SLS, STR, DAT and PRX1 reached a maximal level with 0.1 μg/mL 3 kDa chitooligosaccharides treatment. All these results suggest that spraying Catharanthus roseus leaves with chitooligosaccharides, especially 0.1 μg/mL of 3 kDa chitooligosaccharides, may effectively improve the pharmaceutical value of Catharanthus roseus.

Nutritional Improvement of Bean Sprouts by Using Chitooligosaccharide as an Elicitor in Germination of Soybean (Glycine max L.)

Soybean sprouts are among the healthiest foods consumed in most Asian countries. Their nutritional content, especially bioactive compounds, may change according to the conditions of germination. The purpose of this study was to test the effect of chitooligosaccharide with different molecular weight and dosage on nutritional quality and enzymatic and antioxidant activities of soybean sprouts. The chitooligosaccharide elicitor strongly stimulated the accumulation of vitamin C, total phenolics, and total flavonoid. The stimulation effect was correlated with the molecular weight and concentration of chitooligosaccharide. With treatment of 0.01% of 1 kDa chitooligosaccharide, the nine phenolic constituents and six isoflavone compounds were significantly increased. The antioxidant capacity (DPPH radical and hydroxyl radical scavenging activity) and antioxidase activities (catalase and peroxidase) of soybean sprouts were also enhanced after treatment with chitooligosaccharide. The degree of chitooligosaccharide-induced elicitor activity increased as the molecular weight of chitooligosaccharide decreased. These results suggest that soaking soybean seeds in a solution of chitooligosaccharide, especially in 0.01% of 1 kDa chitooligosaccharide, may effectively improve the nutritional value and physiological function of soybean sprouts.

Description and functional analysis of the transcriptome from malting barley

The present study aimed to establish an early model of the malting barley transcriptome, which describes the expression of genes and their ontologies, identify the period during malting with the largest dynamic shift in gene expression for future investigation, and to determine the expression patterns of all starch degrading enzyme genes relevant to the malting and brewing industry. Large dynamic increases in gene expression occurred early in malting with differential expressed genes enriched for cell wall and starch hydrolases amongst many malting related categories. Twenty-five of forty starch degrading enzyme genes were differentially expressed in the malting barley transcriptome including eleven α-amylase genes, six β-amylase genes, three α-glucosidase genes, and all five starch debranching enzyme genes. Four new or novel α-amylase genes, one β-amylase gene (Bmy3), three α-glucosidase genes, and two isoamylase genes had appreciable expression that requires further exploration into their potential relevance to the malting and brewing industry.

Seed 'primeomics': plants memorize their germination under stress

Seed priming is a pre-germination treatment administered through various chemical, physical and biological agents, which induce mild stress during the early phases of germination. Priming facilitates synchronized seed germination, better seedling establishment, improved plant growth and enhanced yield, especially in stressful environments. In parallel, the phenomenon of 'stress memory' in which exposure to a sub-lethal stress leads to better responses to future or recurring lethal stresses has gained widespread attention in recent years. The versatility and realistic yield gains associated with seed priming and its connection with stress memory make a critical examination useful for the design of robust approaches for maximizing future yield gains. Herein, a literature review identified selenium, salicylic acid, poly-ethylene glycol, CaCl₂ and thiourea as the seed priming agents (SPRs) for which the most studies have been carried out. The average priming duration for SPRs generally ranged from 2 to 48 h, i.e. during phase I/II of germination. The major signalling events for regulating early seed germination, including the DOG1 (delay of germination 1)-abscisic acid (ABA)-heme regulatory module, ABA-gibberellic acid antagonism and nucleus-organelle communication are detailed. We propose that both seed priming and stress memory invoke a 'bet-hedging' strategy in plants, wherein their growth under optimal conditions is compromised in exchange for better growth under stressful conditions. The molecular basis of stress memory is explained at the level of chromatin reorganization, alternative transcript splicing, metabolite accumulation and autophagy. This provides a useful framework to study similar mechanisms operating during seed priming. In addition, we highlight the potential for merging findings on seed priming with those of stress memory, with the dual benefit of advancing fundamental research and boosting crop productivity. Finally, a roadmap for future work, entailing identification of SPR-responsive varieties and the development of dual/multiple-benefit SPRs, is proposed for enhancing SPR-mediated agricultural productivity worldwide.

Enhanced thermotolerance of Arabidopsis by chitooligosaccharides-induced CERK1n-ERc fusion gene

Heat stress is a major growth-limiting factor for most crops over the world. Chitin elicitor receptor kinase 1 (CERK1) is a chitin/chitooligosaccharides receptor, and ERECTA (ER) plays a crucial role in plant resistance to heat stress. In the present study, a chitooligosaccharides-induced CERK1n-ERc fusion gene was designed and synthesized, in which the extracellular domain and transmembrane domain of CERK1 gene is connected with the response region of ER gene. We successfully constructed the CERK1n-ERc fusion gene by Overlap PCR and introduced it into Arabidopsis by Agrobacterium-medicated infection. Genetically modified (GM) plants had a greater germination rate and germination index, as well as a shorter mean germination time, indicating that they had a better thermotolerance compared with the wild-type (WT) lines under heat stress. Moreover, the GM lines showed a lower level of hydrogen peroxide (H₂O₂) and relative electrolyte leakage (REL), suggesting that they were in better state compared with the WT plants when exposed to high temperature. UPLC-MS/MS was employed to assess the phytohormone level, suggesting that the GM lines acquired a better thermotolerance via jasmonic acid (JA) signaling pathways. In general, we constructed a COS-induced fusion gene to enhance the thermotolerance of Arabidopsis during seed germination and postgermination growth.

Recognition Pattern, Functional Mechanism and Application of Chitin and Chitosan Oligosaccharides in Sustainable Agriculture

Background:

Application of chitin attracts much attention in the past decades as the second abundant polysaccharides in the world after cellulose. Chitin oligosaccharides (CTOS) and its deacetylated derivative chitosan oligosaccharides (COS) were shown great potentiality in agriculture by enhancing plant resistance to abiotic or biotic stresses, promoting plant growth and yield, improving fruits quality and storage, etc. Those applications have already served huge economic and social benefits for many years. However, the recognition mode and functional mechanism of CTOS and COS on plants have gradually revealed just in recent years.

Objective:

Recognition pattern and functional mechanism of CTOS and COS in plant together with application status of COS in agricultural production will be well described in this review. By which we wish to promote further development and application of CTOS and COS–related products in the field.

Chitin degradation potential and whole-genome sequence of Streptomyces diastaticus strain CS1801

The aim of this study was to evaluate the chitin degradation potential and whole-genome sequence of Streptomyces diastaticus strain CS1801, which had been screened out in our previous work. The results of fermentation revealed that CS1801 can convert the chitin derived from crab shells, colloidal chitin and N-acetylglucosamine to chitooligosaccharide. Additional genome-wide analysis of CS1801 was also performed to explore the genomic basis for chitin degradation. The results showed that CS1801 possesses a chromosome with 5,611,479 bp (73% GC) and a plasmid with 1,388,284 bp (73% GC). The CS1801 genome consists of 7584 protein-coding genes, 90 tRNA and 21 rRNA operons. In addition, the results of genomic CAZyme analysis indicated that CS1801 comprises 103 glycoside hydrolase family genes, which could regulate the glycoside hydrolases that contribute to chitin degradation. The whole-genome information of CS1801 could highlight the mechanism underlying the chitin degradation activity of CS1801, strongly indicating that CS1801 is characterized by a substantial number of genes encoding chitinases and the complete metabolic pathway of chitin, conferring CS1801 with promising potential applicability in chitooligosaccharide production.

Improvement of barley (Hordeum vulgare L.) germination by application of biochar leacheate in steeping solution to upgrade malt quality

OBJECTIVE

To investigate an improvement of barley germination by application of biochar leacheate in the steeping solution for upgrading malt quality.

RESULTS

Barley germination was improved when biochar leacheate was used in the steeping water during the first steeping cycle. A clear decrease in the time to reach 50% of final germination percentage was detected due to an addition of biochar leacheate, but no significant difference was observed in the percent germination at the end of germination. Hydrolase activities including α-amylase, proteinase and β-glucanase in barley grains were maximally increased during the malting process when 10% biochar leacheate was added to the first steeping water. The wort yielding indexes including both glucose and maltose content and the free amino nitrogen content were significantly increased but the β-glucan content was significantly decreased at a level of p < 0.05 when 10% biochar leacheate was added to the steeping water.

CONCLUSIONS

Biochar leacheate could be used as a stimulator in the steeping solution during the first steeping cycle to improve barley germination and so upgrade malt quality.

Beer-spoilage characteristics of Staphylococcus xylosus newly isolated from craft beer and its potential to influence beer quality

To meet demands for fresh flavor and unique taste from beer consumer, there is an increase in the popularity of craft beer, which is more susceptible to microbial contamination than the industry beer. A beer-spoilage strain was isolated from craft beer and identified as Staphylococcus xylosus strain BS7. The isolate BS7 showed that high beer-spoilage ability at low temperature (4°C), low pH (4.0) and high ethanol concentration (7.0%, v/v). Compared with the other known strains of S. xylosus, strain BS7 was resistant to hop compounds and had an evolutionary stability in hop resistance. Strain BS7 was able to grow quickly and utilizes nutrients in commercial beer, produces organic acids and biogenic amines, and changes beer flavor profile. These results suggest that S. xylosus strain BS7 is a beer-spoilage strain with the danger, which can lead to the beer-spoilage issues during craft beer production.

A review on the preparation of chitosan oligosaccharides and application to human health, animal husbandry and agricultural production

Chitosan oligosaccharides (COS) are the degraded products of chitin or chitosan prepared by chemical or enzymatic hydrolysis. As compared to chitosan, COS not only exhibit some specific physicochemical properties such as excellent water solubility, biodegradability and biocompatibility, but also have a variety of functionally biological activities including anti-inflammation, anti-bacteria, immunomodulation, neuroprotection and so on. This review aims to summarize the preparation and structural characterization methods of COS, and will discuss the application of COS or their derivatives to human health, animal husbandry and agricultural production. COS have been demonstrated to prevent the occurrence of human health-related diseases, enhance the resistance to diseases of livestock and poultry, and improve the growth and quality of crops in plant cultivation. Overall, COS have presented a broad developmental potential and application prospect in the healthy field that deserves further exploration.

Improved hydrolase activity in barley and reduced malting time by adding phytase as an activator during malting steeping

OBJECTIVES

Exogenous phytase improved the activity of hydrolases to decrease the malting time.

RESULTS

Treatment with phytase during barley steeping increased activity of hydrolases (α-/β-amylase, proteinase, β-glucanase and xylanase) in green malt. Maximal activity was observed for α-/β-amylase, β-glucanase and xylanase with 0.8 U phytase/g and proteinase with 1.2 U phytase/g. Phytase promoted acrospire growth of green malt and reduced malting process with 0.8 U phytase/g in 96 h, which is 24 h less than the control. No significant variation of malt quality was found between control malt and malt treated with 0.8 U/g or 1.2 U phytase/g (P > 0.05), which makes application of exogenous phytase during steeping process as a good option for reducing malting time.

CONCLUSION

Adding phytase during steeping process increases the activity of hydrolases, which reduces malting time without impacting on malt quality.