Substrate Wheat Bran Research Articles

Synergistic effects of distinct arabinofuranosidase specificities in lignocellulose degradation by different hemicellulases.

Arabinoxylan is a prevalent hemicellulose type, notably heterogeneous and resistant to biodegradation. Arabinofuranosidases (Abfs) remove arabinofuranosyl decorations of arabinoxylan, thus enabling hydrolysis by xylanases. However, a variety of Abf and xylanase specificities have emerged in recent years, necessitating a deeper understanding of their role in biomass degradation. This work investigates the biochemical features of TtAbf43 from Thermothelomyces thermophila, which specifically removes the O-3-linked arabinofuranose moieties from di-substituted xylopyranoses. The enzyme also exhibited secondary hydrolytic activity on o-nitrophenyl-β-d-xylopyranoside and arabinan. The hydrolysis of pretreated wheat and corn bran substrates was assessed using TtAbf43 and AnAbf51, two enzymes with distinct catalytic specificities. The Abfs enhanced the performance of endo-xylanases TmXyn10 and AnXyn11, promoting the release of xylo-oligomers, while the xylanases, in turn, stimulated arabinose release by the Abfs. Additionally, the Abfs facilitated the endo- and exo-activities of the bifunctional xylobiohydrolase/glucuronoxylanase TtXyn30A for the release of xylobiose and short aldouronic acids from biomass. AnAbf51 also acted in synergy with the acetyl xylan esterase OCE6 and the exo-deacetylase TtCE16B in debranching enzymatically derived oligomers from lignocellulose, whereas TtAbf43 remained unaffected by the esterases. These diverse synergistic relationships among different hemicellulases could assist the development of new enzymatic approaches for efficient biomass valorization.

A preliminary study on the degradation of AFB1 by Tenebrio molitor, Rhizopus oryzae and Trichoderma reesei

Abstract Recently, genus Aspergillus, a fungus capable of producing aflatoxins, secondary highly toxic metabolites, has spread to new areas. These areas became suitable habitats due to the recent climate changes. The use of aflatoxin-contaminated crops is a cause of great concern in guaranteeing food safety and is responsible for major economic losses along the supply chain. For this reason, several strategies have been investigated to utilize these contaminated products as a possible food or feed resource by reducing or eliminating their aflatoxin content, but with limited relevant success. The presented study was aimed to evaluate a combination of biological processes to use aflatoxin B1 contaminated crops for their reintroduction into the production chain. The high tolerance to AFB1 and the apparent lack of accumulation in yellow mealworm larvae, reared on wheat bran substrates, spiked with increasing AFB1 concentration (0, 125, 250, 500 μg/kg) to obtain proteins of high biological value. Subsequently, the aflatoxin-degrading capacity of Rhizopus oryzae and Trichoderma reesei was applied to insect breeding waste (frass) in a fermentation process to ensure further utilization of biohazardous frass as soil conditioner. Individually, each process proven to be able to reduce the AFB1 present by about 80%, while the combination of the two approaches ensured the total degradation of aflatoxin B1-contaminated substrate and frass, which resulted in the possible production of biomass, that could be used for the feed and agricultural industry.

Characterization of Detergent-Compatible Lipases from Candida albicans and Acremonium sclerotigenum under Solid-State Fermentation.

The purpose of this study was to compare and explore the potential of two distinct lipases at industrial levels after their production using wheat bran substrate in solid-state fermentation. Lipases from Candida albicans (C. albicans) and Acremonium sclerotigenum (A. sclerotigenum) were characterized to assess their compatibility and suitability for use in laundry detergents. The effects of pH, temperature, metal ions, inhibitors, organic solvents, and various commercially available detergents on these lipases were studied in order to compare their activity and stability profiles and check their stain removal ability. Both lipases remained stable across the wide pH (7-10) and temperature (30-50 °C) ranges. C. albicans lipase exhibited optimum activity (51.66 U/mL) at pH 7.0 and 37 °C, while A. sclerotigenum lipase showed optimum activity (52.12 U/mL) at pH 8.0 and 40 °C. The addition of Ca2+ and Mg2+ ions enhanced their activities, while sodium dodecyl sulfate (SDS) and ethylenediamine tetraacetic acid (EDTA) reduced their activities. Lipase from both strains showed tolerance to various organic solvents and considerable stability and compatibility with commercially available laundry detergents (>50%); however, A. sclerotigenum lipase performed slightly better. Characterization of these crude lipases showed nearly 60% relative activity after incubation for 2 h in various detergents, thus suggesting their potential to be employed in the formulation of laundry detergents with easy and efficient enzyme production. The production of thermostable and alkaline lipases from both strains makes them an attractive option for economic gain by lowering the amount of detergent to be used, thus reducing the chemical burden on the environment.

HOUSE FLY LARVAE HARVEST YIELD USING THREE DIFFERENT RATIONS OF WHEAT BRAND AND PIG MANURE AS LARVAL DEVELOPMENT MEDIA

The aim of the research was to compare the yields of house fly larvae using different proportions of wheat bran and swine feces as larval development medium, in a randomized block experimental design with five replications: A-100 % wheat bran; B- 50% wheat bran and 50% swine feces; C- 100% swine feces. Measurements of the temperature of the substrates, as well as the temperature and relative humidity of the place where the flies were developing were made every 24 hours. The larval yield per m2 and kg of substrate, (including the water used to moisten the larval media) were also registered. The wheat bran substrate presented the highest temperature values (36.78 oC), with values above the ambient temperature. The relative humidity varied between 44 and 68%. The amount of water used per square meter was 28.75; 27.72 and 28.87 L for A, B and C treatments, respectively. The highest yield for all substrates was obtained during the first harvest after six days with the highest values for treatment B with 2869.11 g m²-1 and 181.16 g kg-1, respectively. The transformation of the crude protein of the substrates by the fly larvae was between 28.0 and 41.0%, with the highest value for treatment B with 2869,11 g m² -1 and 181,16 g kg2-1 . No presence of pathogenic agents was observed in the harvested larvae.

Carob (Ceratonia siliqua) as Functional Feed Is Beneficial in Yellow Mealworm (Tenebrio molitor) Rearing: Evidence from Growth, Antioxidant Status and Cellular Responses.

In terms of sustainability and circular economy, agricultural by-products may be efficiently reused in insects’ rearing for high-quality protein sources in human diet and animal feeds. The present study aimed to explore whether the utilization of carob pods as feeding substrate may beneficially affect Tenebrio molitor’s growth, nutritional value, antioxidant status and cellular responses. Increasing levels of milled whole carob pods (0, 25, 50, 75, 100%) were used as alternative wheat bran (control) substrates for yellow mealworm rearing, while growth performance, proximate composition, total phenolic content, antioxidant enzyme activity and the expression of stress- and apoptotic-related proteins were evaluated in larvae. The results showed that carob pods’ content up to 75% did not significantly differentiate larvae weight, development time and total dry matter. Larvae total phenolic content and antioxidant activity exhibited a significant increase at 75% content. Although the antioxidant enzymes’ activity decreased at both 25 and 50% levels, higher carob content levels (75 and 100%) resulted in no significant changes compared to the control. Carob pods led to decreased apoptotic indicators and the low expression of most stress-related proteins compared to the control. The present findings demonstrate that carob pods and their antioxidant properties exert beneficial effects on T. molitor’s rearing and nutritional status, although 100% carob content may impact adversely the larvae due to the high amounts of carob tannins.

Tamarindus indica seed induced tannase production from Aspergillus niger

Introduction and Aim: Tannase an inducible extracellular microbial enzyme is extensively produced by different fermentation techniques and finds wide applications in food, pharmaceutical and textile industries. The present investigation focused on tannase production from Aspergillus niger through submerged (SmF) and solid-substrate fermentation (SSF) using different media. The enzyme was also induced using tamarind seeds. Methods and Materials: Aspergillus niger was grown in various submerged media such as Tannase screening broth (TSB), Czapek Dox broth (CDB), Sabouraud’s Dextrose broth (SDB) and Potato Dextrose broth (PDB). Among solid substrates wheat bran, ground nut cake, coconut cake and tamarind seed powder used individually and in mixed form. Results: In SmF, the highest tannase activity of 713.6 U/ml was found in TSB, followed by CDB (590.6 U/ml), SDB (465.6 U/ml) and PDB (424.8 U/ml). In all media highest activity was on 4th day while in SDB on 6th day of incubation. Tannase production was also carried out in CDB supplemented with 2% processed tamarind seeds to test for its induction, where the highest (936 U/ml) activity was in raw seeds than in processed seeds. SSF in mixed substrates showed highest activity of 1708.6 U/gds followed by 1278.0, 986.5, 826.3 and 723.6 U/gds in tamarind seeds, wheat bran, ground nut cake and coconut cake, respectively. Conclusion: Tannase enzyme is found to be induced by raw tamarind seed supplemented submerged medium than with processed seeds. In SSF with tamarind seed showed the highest tannase activity indicating that the tannic acid present in raw seeds serve to induce Aspergillus niger for increased production of tannase enzyme.

Valorization of agricultural residues using Myceliophthora thermophila as a platform for production of lignocellulolytic enzymes for cellulose saccharification

The use of lignocellulosic agricultural residues is emerging as a low-cost, sustainable, and eco-friendly approach for the production of microbial enzymes and other chemicals. In this study, the production of enzymes with lignocellulolytic potential and the secretome profile of the thermophilic fungus Myceliophthora thermophila were evaluated in solid-state cultivation on agricultural residues such as rice straw, soy straw, and wheat bran. In addition, the saccharification potential of the extracts was evaluated. The analysis of enzymatic activities (peptidase, lipase, amylase, CMCase, FPase, β-glucosidase, xylanase, pectinase, and laccase) and the 66 proteins identified in the secretome reinforced the hydrolytic and oxidative properties of the enzymatic lignocellulolytic arsenal produced by M. thermophila. The extracellular extract grown on rice straw obtained after 72 h of solid-state bioprocess achieved 46% saccharification of wheat bran substrate. Furthermore, the overall performance of the wheat bran extract (24 h) indicates the relevance of the CMCase, FPase and xylanase activities in saccharification processes. These results highlight the potential of M. thermophila as a platform for the production of enzymes with biotechnological potential, especially for lignocellulose degradation and cellulose saccharification. Solid-state bioprocess allows exploring agro-industrial residues, as a matrix and source of nutrients, for the enzyme production and emphasizes the possibility of adding value to agricultural waste. Moreover, the use of M. thermophila in solid-state bioprocesses can still be widely explored and optimized as a platform to scale up the production of cheapest fungal enzymes.

Optimization of pullulanase production by Aspergillus flavus under solid-state fermentation

Pullulanase is a promising candidate for industrial applications. But less yield and high cost limited its application. Hence, the present study aims to optimize nutrients for increasing the yield of fungal pullulanase to resolve these limitations. The findings of Plackett Burman Design showed that only 5 of 19 nutrients influenced the yield of pullulanase significantly. Box-Behnken Design (BBD) was implemented to establish the optimal concentration of the significant nutrients. After statistical optimization for KH2PO4, yeast extract, peptone, and MnSO4, supplemented in the substrate wheat bran, the overall increase in yield was 1.63 fold. In all the flasks (500 to 5000 mL capacity containing 10–100 g dry substrate), almost the same yield has been produced (647.00 ± 25.139 U/gds) suggesting that the production of pullulanase can readily be scaled up under optimized conditions. This is the first nutrient optimization study of pullulanase production by Aspergillus flavus in solid state fermentation using wheat bran.

Characterisation of alpha-amylase inhibitor from Streptomyces xinghaiensis AAI2 in solid substrate

Alpha-amylase inhibitors, which play metabolic roles in the organisms that produce them, by impeding the activity of alpha-amylase enzyme, have been isolated from many sources including plants and microorganisms. They vary in characteristics and applications based on their sources though there are characters that appear similar despite the source. Alpha-amylase inhibitor was produced by Streptomyces xinghaiensis AAI2 cultured on wheat bran substrate supplemented with a nutrient basal medium which was also used to adjust both the moisture content (73%) and initial pH (6.48) of the medium. The extract obtained was purified using standard purification techniques (ammonium sulphate precipitation, dialysis and column chromatography). Characteristics such as effects of pre-incubation and pH, total protein, specific activity, total activity, percentage yield, molecular weight and kinetics were determined. The alpha-amylase inhibitor produced was found to occur in isoforms having molecular weights of 14.2 and 56 kDa. Total protein, specific activity and percent yield obtained were 0.19 mg/mL, 745.11 AIU and 2.27% respectively. The optimum activity was obtained at pH 8.0 and in the presence of Cobalt and Calcium ions while pre-incubation for 10 min was best with no further improvement in the activity beyond this time. The inhibitor exerted a non-competitive type of inhibition.

Deciphering the Amendment-Induced Secretion of Ligninolytic Enzymes by Pleurotus pulmonarius

Pleurotus pulmonarius belonging to the white-rot fungal basidiomycetes group secretes extracellular ligninolytic enzymes for the degradation of agroresidues. The present study was carried out to evaluate the efficacy of different agro-residues for the enhanced production of ligninolytic enzymes and to authenticate their ability by protein analysis. The morphological and molecular sequences of white-rot fungi were characterised. Besides, the efficacy of organic and inorganic amendments in the secretion of ligninolytic enzymes by P. pulmonarius was characterised using SDS-PAGE and native PAGE analysis. The characterised strain of P. pulmonarius secreted enhanced laccase enzyme levels in the liquid medium through supplementation with organic and inorganic amendments. Wheat bran and groundnut cake each @5% enhanced secretions of Laccase, LiP and MnP. Copper sulphate at 150 μM enhanced the laccase enzyme and at 100 μM enhanced the LiP enzyme level by P. pulmonarius. Similarly, supplementation with manganese sulphate at 150 μM enhanced laccase, LiP and MnP enzyme levels compared to control. SDS-PAGE results showed protein banding patterns in the range of 50–85 kDa for the Lac enzyme in samples drawn from wheat bran and groundnut cake-supplemented substrates. Native PAGE results of laccase enzymes also showed that wheat bran (5%) + groundnut cake (5%) + CuSO4 (150 M) + MnSO4 (150 M) induced four laccase isozymes. Supplementing organic and inorganic amendments to the substrates would enhance the secretion of laccase enzyme that would aid in better breakdown of lignin.

Interspecific hybridization between Ganoderma lingzhi and G. applanatum through protoplast fusion.

Interspecific hybridization between Ganoderma lingzhi and G. applanatum was attempted through polyethylene glycol (PEG) induced fusion technique. The protoplast isolation procedure was simplified, and we obtained a significant number of protoplasts from both Ganoderma species. The number of protoplasts obtained was 5.27 ± 0.31 × 107/mL in G. lingzhi and 5.57 ± 0.49 × 106/mL in G. applanatum. Osmotic stabilizer NaCl (0.4M) at pH 5.8 and enzymolysis time 3.5h have supported high frequency of protoplast regeneration. G. lingzhi and G. applanatum regeneration frequency was 1.73 ± 0.04% and 0.23 ± 0.02%, respectively. 40% of PEG induced high number of protoplast fusion the regeneration frequency was 0.09% on a minimal medium. Two hundred fifty-two fusant colonies were isolated from the following four individual experiments. Among them, ten fusants showed the mycelial morphological difference compared to their parents and other fusant isolates. The fruiting body could be generated on oak sawdust and wheat bran substrate, and a few of them showed recombined morphology of the parental strains. The highest yield and biological efficacy (BE) were recorded in GF248, while least in GF244. The hybridity of the fusant was established based on mycelia, fruiting morphology, and PCR fingerprinting. ISSR and RAPD profile analysis of ten fusants and parents depicted that fusants contained polymorphic bands, which specified the rearrangement and deletion of DNA in the fusants. A Dendrogram was constructed based on the RAPD profile, and the clustering data exhibited two major clusters: cluster I included the G. lingzhi and Cluster II, including the G. applanatum and fusant lines. Total polysaccharide (α, β and total glucan) content was compared with fusants and parental strains. The present study highlighted the efficient methods for protoplast isolation from Ganoderma species. PEG-induced fusants showed high polymorphic frequency index, while the phenotypic characters showed high similarity to G. applanatum. A significant difference was observed in the mushroom yield and its total polysaccharide between the fusants and parental strains.

β-Galactosidase-Producing Isolates in Mucoromycota: Screening, Enzyme Production, and Applications for Functional Oligosaccharide Synthesis.

β-Galactosidases of Mucoromycota are rarely studied, although this group of filamentous fungi is an excellent source of many industrial enzymes. In this study, 99 isolates from the genera Lichtheimia, Mortierella, Mucor, Rhizomucor, Rhizopus and Umbelopsis, were screened for their β-galactosidase activity using a chromogenic agar approach. Ten isolates from the best producers were selected, and the activity was further investigated in submerged (SmF) and solid-state (SSF) fermentation systems containing lactose and/or wheat bran substrates as enzyme production inducers. Wheat bran proved to be efficient for the enzyme production under both SmF and SSF conditions, giving maximum specific activity yields from 32 to 12,064 U/mg protein and from 783 to 22,720 U/mg protein, respectively. Oligosaccharide synthesis tests revealed the suitability of crude β-galactosidases from Lichtheimia ramosa Szeged Microbiological Collection (SZMC) 11360 and Rhizomucor pusillus SZMC 11025 to catalyze transgalactosylation reactions. In addition, the crude enzyme extracts had transfructosylation activity, resulting in the formation of fructo-oligosaccharide molecules in a sucrose-containing environment. The maximal oligosaccharide concentration varied between 0.0158 and 2.236 g/L depending on the crude enzyme and the initial material. Some oligosaccharide-enriched mixtures supported the growth of probiotics, indicating the potential of the studied enzyme extracts in future prebiotic synthesis processes.

Dietary zinc enrichment reduces the cadmium burden of mealworm beetle (Tenebrio molitor) larvae

The industrial production of Tenebrio molitor L. requires optimized rearing and processing conditions to generate insect biomass with high nutritional value in large quantities. One of the problems arising from processing is a tremendous loss in mineral accessibility, affecting, amongst others, the essential trace element Zn. As a feasible strategy this study investigates Zn-enrichment of mealworms during rearing to meet the nutritional requirements for humans and animals. Following feeding ZnSO4-spiked wheat bran substrates late instar mealworm larvae were evaluated for essential micronutrients and human/animal toxic elements. In addition, growth rate and viability were assessed to select optimal conditions for future mass-rearing. Zn-feeding dose-dependently raised the total Zn content, yet the Znlarvae/Znwheat bran ratio decreased inversely related to its concentration, indicating an active Zn homeostasis within the mealworms. The Cu status remained stable, suggesting that, in contrast to mammals, the intestinal Cu absorption in mealworm larvae is not affected by Zn. Zn biofortification led to a moderate Fe and Mn reduction in mealworms, a problem that certainly can be overcome by Fe/Mn co-supplementation during rearing. Most importantly, Zn feeding massively reduced the levels of the human/animal toxicant Cd within the mealworm larvae, a technological novelty of outstanding importance to be implemented in the future production process to ensure the consumer safety of this edible insect species.

Biotransformation of aflatoxin B1 by Lactobacillus helviticus FAM22155 in wheat bran by solid-state fermentation

Lactobacillus helveticus FAM22155 was the most efficient among five lactic acid bacteria at removing aflatoxin B1 (AFB1) during solid-state fermentation on wheat bran substrate. The mechanism of removal was explored by comparing different fermentation modes. Liquid fermentation had little effect on the breakdown of AFB1. However, a protein extract from the fermented bran was equally effective at degrading aflatoxin B1 as living cell digestion. After treatment with heat and protease K, the degrading capacity of the protein extract was significantly reduced. Taken together, the observed biotransformation of AFB1 was mainly associated with proteins produced during bran fermentation. Four products of U-[13C17]-AFB1 were found by mass spectrometry, including Ⅱ-1 (C11H10O4), Ⅱ-2 (C11H10O4), III (C15H12O5), and IV (C14H10O4). These products all lack the lactone ring indicating lower toxicity than aflatoxin B1.

Chitinase production by Trichoderma koningiopsis UFSMQ40 using solid state fermentation.

The chitinases have extensive biotechnological potential but have been little exploited commercially due to the low number of good chitinolytic microorganisms. The purpose of this study was to identify a chitinolytic fungal and optimize its production using solid state fermentation (SSF) and agroindustry substrate, to evaluate different chitin sources for chitinase production, to evaluate different solvents for the extraction of enzymes produced during fermentation process, and to determine the nematicide effect of enzymatic extract and biological control of Meloidogyne javanica and Meloidogyne incognita nematodes. The fungus was previously isolated from bedbugs of Tibraca limbativentris Stal (Hemiptera: Pentatomidae) and selected among 51 isolated fungal as the largest producer of chitinolytic enzymes in SSF. The isolate UFSMQ40 has been identified as Trichoderma koningiopsis by the amplification of tef1 gene fragments. The greatest chitinase production (10.76U gds-1) occurred with wheat bran substrate at 55% moisture, 15% colloidal chitin, 100% of corn steep liquor, and two discs of inoculum at 30°C for 72h. Considering the enzymatic inducers, the best chitinase production by the isolated fungus was achieved using chitin in colloidal, powder, and flakes. The usage of 1:15g/mL of sodium citrate-phosphate buffer was the best ratio for chitinase extraction of SSF. The Trichoderma koningiopsis UFSMQ40 showed high mortality of M. javanica and M. incognita when applied to treatments with enzymatic filtrated and the suspension of conidia.

Optimized Solid-State Fermentation Medium Enhances the Multienzymes Production from Penicillium citrinum and Aspergillus clavatus.

Filamentous fungi play an important role in the production of a range of useful extracellular hydrolytic enzymes for wide industrial applications. The Western Ghats region is known for its rich microbial biodiversity and could be a potential source of several useful fungi that could be exploited for the production of industrially important enzymes. From this soil, we aimed at the isolation of multienzyme producing fungi, optimization of the culture conditions using solid-state fermentation (SSF), partial purification of enzymes and characterization by zymography. Out of seven fungal strains, two isolates, namely Penicillium citrinum and Aspergillus clavatus, were found to produce amylase and cellulase enzymes maximally. The effect of different physicochemical parameters on the production of amylase and cellulase was investigated and the maximum production of multienzymes was achieved in wheat bran substrate. The newly formulated and optimized medium increased the multienzyme production in P. citrinum and A. clavatus as compared to medium with individually optimized parameters. Further, for the first time, different isoforms of amylase and cellulase have been identified from P. citrinum and A. clavatus by zymography. In summary, the present study showed that the filamentous fungi can utilize the industrial waste product such as wheat bran as the substrate for multienzymes production by SSF and could be a promising source of enzymes for biotechnological applications.

Production of high-value bioproducts enriched with \u03b3-linolenic acid and \u03b2-carotene by filamentous fungi Umbelopsis isabellina using solid-state fermentations

Solid-state fermentation is a useful tool for utilizing different plant-based materials as cultivation substrates in order to produce potentially high-value fermented bioproducts. The aim of the present study was to successfully prepare various types of such bioproducts, using a zygomycetous strain Umbelopsis isabellina CCF2412. Various legume and cereal substrates were utilized effectively, while a few of them were obtained from agricultural waste, which is particularly advantageous from ecological and economic point of view. A common feature of the produced fermented materials was the increased content of different polyunsaturated fatty acids and carotenoid pigments in these bioproducts. Subsequent to the optimization of the solid-state fermentation process using cornmeal as the cultivation substrate, bioproducts enriched with γ-linolenic acid (11.45 mg γ-linolenic acid per gram of bioproduct), β-carotene (50.90 μg β-carotene per gram of bioproduct), and various microbial sterols were obtained. Appropriate n–6/n–3 acid ratio and enrichment of other microbial substances, such as the pigments and sterols mentioned above, in the fermented bioproducts widens the applicability of these bioproducts in different industries. The fermented cereal bioproducts produced in the present study from fermented wheat bran substrate were used for evaluating their application as feed for broiler chicken, and satisfactory results were obtained. Therefore, the present study creates novel opportunities for improving the quality of fermented bioproducts obtained during solid-state fermentation processes, especially for application in the feed industry.

Optimization of Cellulose Production by Curvularia pallescens Isolated from Textile Effluent

Introduction: Celluloses are important industrial enzymes and find application in several industrial processes. Effects of pH, temperature, incubation time, source of carbon and nitrogen were tested in submerged fermentation process in the production of cellulose by Curvularia pallescens isolated from textile effluent.
 Aims: The present study was attempted in a fungus; Curvularia pallescens isolated from textile effluent for maximizing its production under optimal conditions in submerged fermentation by using inexpensive substrate wheat bran.
 Study Design: The production medium was prepared in distilled water, supplemented with 4.5% wheat bran, 0.05% KCl, 0.2% KH2PO4, (carbon source), yeast extract (nitrogen source), maintained with pH of 5.5 and incubated at 28ºC for 120 h was found optimal for the production of cellulose.
 Results: The test fungus achieved maximum FPA activity followed by cellobiohydrolase, endoglucanase and β-glucosidase activity at 46.76, 42.06, 26.94 and 3.56 U/ml respectively at pH 5.5 (Fig. 4). The temperature of 280C produced maximum cellulase activity. Highest activity recorded was of FPA (38.94 U/ml), followed by cellobiohydrolase (30.29 U/ml), endoglucanase (22.41 U/ml), and β-glucosidase (3.98 U/ml). The effect of process parameters such as the effect of temperature, pH and inoculum size was investigated. Maximum cellulase and xylanase having an enzyme activity of 694.45 and 931.25 IU, respectively, were produced at 30ºC incubation temperature.
 Conclusion: The effect of process parameters such as effect of temperature, pH and inoculum size was also investigated. The production of primary metabolites by microorganisms is highly influenced by their growth, which is determined by the availability of the nutrients in the substrates.

Solid state fermentation of amylase production from Bacillus subtilis D19 using agro-residues

The selected bacterial strain, Bacillus subtilis D19 was inoculated into the solid residues such as, wheat bran, banana peel, orange peel, rice bran and pine apple peel. Among the tested solid wastes, wheat bran showed enhanced the production of amylase (640 U/g) than other tested substrates. The carbon and nitrogen sources were initially screened by traditional method using wheat bran medium. Amylase activity was high in the wheat bran substrate supplemented with starch (670 U/g). The tested nitrogen sources enhanced amylase activity. Among the selected nitrogen sources, yeast extract stimulated maximum production of amylase (594 U/g). In two level full factorial experimental design, maximum activity (1239 U/g) was obtained at pH 9.0, 70% (v/w) moisture, 1% (w/w) starch, 1% (w/w) yeast extract and 5% (v/w) inoculums. Central composite design and response surface methodology was used to optimize the required medium concentration (pH, moisture content of the medium and starch concentrations) for the maximum production of amylase. All three selected variables enhanced amylase production over 3 fold in optimized medium.

Recycling agro-industrial waste to produce amylase and characterizing amylase\u2013gold nanoparticle composite

PurposeAmylase being one of the most important industrial enzymes requires large-scale production. When producing an enzyme, high productivity, high purity and low production costs need to be considered. This study focuses on comparing various agro-industrial waste substrates, for production of alpha-amylase using Bacillus amyloliquefaciens. Moreover, it studies the stability and activity of amylase–gold nanoparticles composite.MethodsThis study is divided into two parts, in the first part various agro-industrial waste substrates, such as wheat bran, rice bran and potato peel were used to produce alpha-amylase using solid-state fermentation (SSF). The production of the enzyme was quantified and compared in specific enzyme activity units. In the second part, change in the stability and activity of amylase in enzyme–gold nanoparticles (AuNPs) composite has been discussed.ResultsHighest enzyme production was observed in wheat bran and potato peel substrate with specific enzyme activity of almost 1.2 U/ug and 1.1 U/ug. Among combination substrates, wheat bran with potato peel showed a high enzyme production of 1.3 U/ug. On the other hand, the optimum temperature for amylase activity shifted to 55 °C in the composite compared to 37 °C for free enzyme.ConclusionsComparison of specific enzyme activity of extracts from various substrates showed that wheat bran alone, and in combination with potato peel, produces active and pure amylases. To stress on various catalytic activities of alpha-amylase, the capability of the enzyme to synthesize gold nanoparticles and the effect of conjugation of the nanoparticle on its optimum catalytic activity are also discussed in this paper.