Solid-state Fermentation Medium Research Articles

Chemical constituents from the soil fungus Penicillium sp. DWS853 and their cytotoxic activity

A total of fourteen compounds, including two previously undescribed depside derivatives penicidepsides A (1) and B (2), three phenyl ether derivatives (3–5), three benzophenone derivatives (6–8), four anthraquinone derivatives (9–12), one flavonoid derivative (13), and one bisnaphthalene derivative (14), were isolated from the solid-state fermentation medium of fungus Penicillium sp. DWS853. The structures of these compounds were determined through comprehensive analysis of UV, HRESIMS, and 1D/2D NMR spectroscopic data, along with quantum-chemical calculations. In vitro bioactivity assays showed that questin (9) exhibits cytotoxicity against human colorectal cancer HCT116 cell line, and can induce apoptosis and inhibit its migration/invasion in a dose-depended manner. The potential target of the active compound was implied to be DNA topoisomerase II, using similarity ensemble search, molecular docking, and quantum chemical calculations.

Simple one-step treatment for saccharification of mango peels using an optimized enzyme cocktail of Aspergillus niger ATCC 9642.

Developing efficient microbiological methods to convert polysaccharide-rich materials into fermentable sugars, particularly monosaccharides, is vital for advancing the bioeconomy and producing renewable chemicals and energysources. This study focused on optimizing the production conditions of an enzyme cocktail from Aspergillus niger ATCC 9642 using solid-state fermentation (SSF) and assessing its effectiveness in saccharifying mango peels through a simple, rapid, and efficient one-step process. A rotatable central composite design was employed to determine optimal conditions of moisture, time, and pH for enzyme production in SSF medium. The optimized enzyme cocktail exhibited cellulase activity (CMCase) at 6.28 U/g, filter paper activity (FPase) at 3.29 U/g, and pectinase activity at 117.02 U/g. These optimal activities were achieved with an SSF duration of 81 h, pH of 4.66, and a moisture content of 59%. The optimized enzyme cocktail effectively saccharified the mango peels without the need for chemical agents. The maximum saccharification yield reached approximately 81%, indicating efficient conversion of mango peels into sugars. The enzyme cocktail displayed consistent thermal stability within the tested temperature range of 30-60°C. Notably, the highest sugar release occurred within 36 h, with glucose, arabinose, galactose, and xylose being the primary monosaccharides released during saccharification. This study highlights the potential application of Aspergillus niger ATCC 9642 and SSF for enzymatic production, offering a simple and high-performance process for monosaccharide production. The optimized enzyme cocktail obtained through solid-state fermentation demonstrated efficient saccharification of mango peels, suggesting its suitability for industrial-scale applications.

Novel strategy to elevate solid state fermentation to produce alkilophilic endoglucanase using date waste feedstocks and peapod extract based nutrient media and expired probiotic strain: Application in fermentable sugar production

Solid waste generation and its impactful management are among the most raised environmental concerns seeking sustainable alternatives in the form of value addition. In this study, a novel strategy has been presented towards enhanced bacterial endoglucanase (EG) production under solid state fermentation (SSF). The EG was produced using the waste probiotic juice of the bacteria Lactobacillus casei strain Shirota on a substrate of waste date pulp and seeds in co-fermentation mode. Additionally, peapod extract has been applied as a nutrient medium to maintain moisture in place of commercial media in SSF. Further, for enhancement in enzyme production, the impact of incubation temperature and pH of the SSF medium have been studied to obtain optimum enzyme activity. Under optimum conditions, bacteria produced 17.2 U/mL EG at a temperature of 37 °C and a pH of 8.0. The raw EG showed pH and thermal stability up to 5 h at 60 °C and pH 8.0. Furthermore, the enzymatic hydrolysis of date pulp released 67.71 g/L fermentable glucose obtained in 24 h of the reaction at 60 °C and pH 8.0. This work may have great significance in the areas of solid waste management and microbe-mediated value addition of waste biomass in the context of hydrolytic enzyme production for biorefinery applications.

A Promising Natural Anticancer Compound Derived from Gymnoascus dankaliensis.

Cancer is the uncontrolled growth of malignant cells and is universally estimated to be a common cause of death. No decisive treatment has been identified to cure cancer; therefore, scientists have focused on developing safe and effective treatments. The activity of natural compounds isolated from living organisms, such as fungi, has been investigated in cancer cells. This study aimed to isolate and analyze natural products, as secondary metabolites (SM), of the fungus Gymnoascus dankaliensis (G. dankaliensis) and identify their activity against SR and HCT-18 (HRT-18) cell lines. G. dankaliensiswas isolated from dung samples and identified using a molecular method. The internal transcribed spacer region was amplified from the isolated genomic DNA and sequenced afterward. The isolate was grown on a rice medium as a solid-state fermentation medium to extract natural metabolite products using the ethyl acetate extraction method. The GC-MS analyzed the compound of the natural extract, and the activity of the natural extract was identified against SR and HCT-18 cell lines. The results revealed the ability of G. dankaliensis to produce a natural product as an SM composed of five compounds. The growth of the treated SR and HCT-8 cell lines with the natural extract was inhibited after incubation for 27 h, with the IC50 being 3.57 and 8.61 µg/mL on the HCT-18 and SR cell lines, respectively. In conclusion, the natural extract isolated from the SM of G. dankaliensis showed activity against cancer cells, affecting the SR and HCT-18 cell lines, compared to the control. These results revealed that the product is a promising anticancer treatment.

Biochemical Properties of Crude Alkaline Protease Produced by Bacillus thuringiensis dendrolimus IP 4A/4B under Solid-State Fermentation Conditions

Objective: This paper aims to, study the biochemical properties of the crude enzyme, extracted from the bacterial strain Bacillus thuringiensis dendrolimus IP 4A/4B, such as the concentration of the enzyme, the duration of the enzymatic reaction, the effect of changing the temperature of the enzymatic reaction and the effect of the pH of the enzymatic reaction medium. Methods: Inoculum preparation, submerged and solid-state fermentation media, enzymes assays spectrophotometrically, protein determination were performed. Results: The results indicated that 0.181mg protein/mL of enzyme produced maximum alkaline protease activity (269U/mL/min) followed by 0.227mg protein/mL enzyme (260U/mL/min). The slope of the first period (up to 5min reaction time) exhibited steeper slope indicating reactions velocity near the theoretical initial velocity (Vmax) that has become lesser in value as the reaction was extended up to 120min. The maximum enzyme activity was at 60°C (246U/mL/min), while decreased gradually to reach (188U/mL/min) at 90°C. It was clear that the optimum pH was 9.0 when glycine-NaOH and Tris-HCl buffers were used. Conclusion: The optimum pH for the enzymatic reaction pH 9 indicates the potential for this crude enzyme to be used in many industries that require an alkaline pH, and at the same time, the optimum temperature for the enzymatic reaction of 60°C enhances this applicability; this temperature is widely available in many industries.

A Method for Improving Microbial Conversion of Diosgenin and Separation and Identification of the Product

Diosgenin, a hydrolysis product from Dioscorea plants, can be used as a precursor of steroid drugs (e.g., progesterone, testosterone, and glucocorticoid). However, traditional acid hydrolysis production wastes water and causes severe environmental pollution. The extraction of diosgenin through microbial transformation is the most green and environmentally friendly method at present. In order to improve the efficiency of the extraction of diosgenin through microbial transformation, we proposed a new method of strain mutagenesis. After mutagenesis, the response surface methodology was used to optimize the solid-state fermentation medium, thereby improving the diosgenin yield. We found that the optimal formulation was 5.5% sucrose, 0.6% NH4H2PO4, and 26.6% wheat bran. The final extraction rate of diosgenin reached 0.439% (the value of diosgenin per g. of starting plant dry material). Compared with 0.338% before optimization, it had increased 1.29 times. Furthermore, two other compounds were isolated from the fermentation products. These were identified as diosgenone (C27H41O3) and yuccagenone (C27H42O3). Traditional diosgenone is obtained through the oxidation of diosgenin with oxalic acid, but the method in this study is directly obtained from Dioscorea rhizome powder. The price of Dioscorea rhizome powder is much lower than diosgenin, thus greatly reducing the cost of obtaining diosgenone. This method provides a basis for subsequent research on other pharmacological compounds.

Antioxidant Profile and Biosafety of White Truffle Mycelial Products Obtained by Solid-State Fermentation.

Solid-state fermentation may produce therapeutic compounds with higher biomass or better product characteristics than those generated by submerged fermentation. The objectives of this study were to analyze the antioxidant activities and biosafety of products obtained by white truffle (Tuber magnatum) solid-state fermentation in media with different ratios of soybean and red adlay. High levels of antioxidant components and high antioxidant activities such as DPPH radical scavenging, ferrous ion chelation, and reducing power were measured in 20 mg/mL water and ethanol extracts of the white truffle fermentation products. When the solid-state fermentation medium contained soybean and red adlay in a 1:3 ratio (S1A3), the fermentation product had more uniform antioxidant compositions and activities by principal component analysis (PCA). In addition, a 200 ppm water extract of the mycelial fermentation product was able to protect zebrafish embryos from oxidative stress induced by 5 mM hydrogen peroxide. Sprague–Dawley rats were fed the mycelial fermentation product for 90 consecutive days, revealing a no-observed-adverse-effect level (NOAEL) of 3000 mg/kg BW/day. Therefore, mycelial products obtained by white truffle solid-state fermentation can be used instead of expensive fruiting bodies as a good source of antioxidant ingredients.

Innovative Artificial-Intelligence- Based Approach for the Biodegradation of Feather Keratin by Bacillus paramycoides, and Cytotoxicity of the Resulting Amino Acids.

The current study reported a new keratinolytic bacterium, which was characterized as Bacillus paramycoides and identified by 16S rRNA, and the sequence was then deposited in the GenBank (MW876249). The bacterium was able to degrade the insoluble chicken feather keratin (CFK) into amino acids (AA) through the keratinase system. The statistical optimization of the biodegradation process into AA was performed based on the Plackett–Burman design and rotatable central composite design (RCCD) on a simple solid-state fermentation medium. The optimum conditions were temperature, 37°C, 0.547 mg KH2PO4, 1.438 mg NH4Cl, and 11.61 days of incubation. Innovatively, the degradation of the CFK process was modeled using the artificial neural network (ANN), which was better than RCCD in modeling the biodegradation process. Differentiation of the AA by high-performance liquid chromatography (HPLC) revealed the presence of 14 AA including essential and non-essential ones; proline and aspartic acids were the most dominant. The toxicity test of AA on the HepG2 cell line did not show any negative effect either on the cell line or on the morphological alteration. B. paramycoides ZW-5 is a new eco-friendly tool for CFK degradation that could be optimized by ANN. However, additional nutritional trials are encouraged on animal models.

Screening of Agro-industrial Wastes and Physical Factors for the Production of α-Amylase from Bacillus licheniformis VO1

Biyokütlenin değerlendirilmesi, çevre kirliliğinin önlenmesi bağlamında büyük ilgi görmektedir. Tarımsal sanayi atıkları ve yan ürünleri çok miktarda meydana gelmekte ve çürümeye bırakıldıklarında çevre kirliliğine neden olmaktadırlar. Katı faz fermantasyon (KFF) teknolojisinde tarımsal sanayi atıklarının kullanımı antibiyotikler, pigmentler, aromalar, amilazlar, proteazlar, selülazlar ve lipazlar gibi endüstriyel açıdan önemli enzimlerin üretiminde çeşitli avantajlar sunmaktadır. α-Amilaz, nişastanın rastgele hidrolizini katalize eden bir enzimdir. Bu enzimler tekstil, kağıt, gıda, biyoyakıtlar, deterjanlar ve ilaç endüstrileri gibi çeşitli biyoteknolojik uygulamalarda kullanılır. Bu çalışmada, seçilen bakteri suşu, Bacillus licheniformis VO1, elma, kavun, muz ve portakal kabuklarının bulunduğu katı faz fermantasyon ortamlarına inoküle edildi ve test edilen katı substratlar arasında en yüksek α-amilaz üretimi elma kabuklarının bulunduğu ortamdan elde edildi. Fermantasyon süresi, fermantasyon sıcaklığı, başlangıç pH, inokülüm oranı, azot, karbon ve metal kaynaklarının etkisi ayrı ayrı incelendi. Maksimum α-amilaz üretimi 45 °C, pH 6.0 ve 48. saatte elde edildi. Elma kabuklarının bulunduğu fermantasyon ortamına eklenen çeşitli karbon ve azot kaynaklarının etkisi incelendiğinde, maksimum α-amilaz üretimi sırasıyla nişasta ve maya özütü bulunan ortamlardan elde edildi. Elde edilen sonuçlar göz önünde bulundurulduğunda, meyve işleme sanayinde meydana gelen elma kabuğu atıklarının katı faz fermantasyonunda (KFF) substrat olarak kullanımı ile Bacillus licheniformis VO1’den α-amilaz üretimi gelecekte çevresel iyileştirme süreçlerinde kullanılmak üzere potansiyel bir aday olarak düşünülebilir.

Production of Bacterial Amylase and Evaluation for Starch Hydrolysis

In starch degrading industry, the first step to be performed is gelatinization of starch granules at elevated temperature. This process tends to form a viscose suspension, thus making mixing and pumping a huge challenge. Therefore, to lower the viscosity of starch paste thermostable enzymes are added for breaking down the polysaccharides into oligosaccharides by a process known as liquefaction. Therefore, the availability of these enzymes can be considered a prerequisite to start successful starch liquefaction and saccharification industry. The main objective of this study was, therefore, to produce efficient microbial amylolytic enzymes for starch hydrolysis. One bacterial isolate designated as BACC 2107 was isolated from locally collected samples. The enzyme has optimum activity at pH of 5.0 and 70°C. The addition of calcium in the reaction mixture was shown to stabilize the enzyme. The isolate BACC 2107 was able to grow under solid-state fermentation (SSF) using wheat bran as a solid substrate. Optimum enzyme production was recorded at 32°C, and at 120 h of incubation and at a moisture content of 75%. Addition of peptone to the SSF medium as an organic nitrogen supplement enhanced enzyme production. The enzyme was used to hydrolyze a 25% (w/v) of starch at 70°C and pH 5.0, and the resulting hydrolysate was analyzed on TLC plates. After 4 h hydrolysis, the TLC chromatogram showed the release of glucose, maltose, maltotriose, and other oligosaccharides, indicating that the enzyme is endo-acting alpha-amylase. The results of this study show that amylase from BACC 2107 has a good potential to be used in starch liquefaction and saccharification processes. The ability of the isolate to grow and produce the enzyme under SSF using cheap agro-industrial wastes could help to greatly reduce the production cost of the enzyme.

KITCHEN WASTE SOLID STATE FERMENTATION BY Aspergillus niger TO PRODUCE ACID PROTEASE

Acid protease production was carried out by solid state fermentation (SSF) with Aspergillus niger using kitchen waste as the principal raw material. The SSF conditions were studied and the optimal one was identified. This study explored effects of different water contents in SSF medium, different inoculum sizes and different fermentation time on acid protease activities by following the one-factor-at-a-time method. Based on the results obtained, the optimal fermentation conditions for the production of c acid protease, were are as follows: 30g of kitchen waste content, 20mL of initial water content, 4mL of inoculum, and 70h ofas fermentation time. Under these fermentation conditions, the activity of the acid protease was 223.518 U.

Fungal-Assisted Valorization of Raw Oil Palm Leaves for Production of Cellulase and Xylanase in Solid State Fermentation Media

As yet, the full potential of raw oil palm frond leaves (OPFL) is not fully explored. This study therefore, evaluated OPFL as cheap and sustainable growth substrate for two novel fungi species to produce cellulase and xylanase under solid-state fermentation (SSF). 18S rRNA, phylogeny and BIOLOG® analyses identified the cellulase and xylanase-producing fungal strains as Trichoderma asperellum UC1 and Rhizopus oryzae UC2. In addition to being more robust and fast-growing, strain UC2 demonstrated rapid spore production and exhibited sustained production of cellulase and xylanase as compared to the fungal strain UC1. Maximum endoglucanase, exoglucanase, β-glucosidase and xylanase activity for strain UC1 were recorded as 59.64 U/g, 9.58 U/g, 118.1 U/g and 175.91 U/g, respectively, while UC2 gave the corresponding enzyme activity of 41.62 U/g, 7.65 U/g, 113.07 U/g and 162.68 U/g. It was apparent that strains UC1 and UC2 grew well under SSF of raw OPFL, envisaging the feasibility of this form of oil palm biomass as growth substrate for fungi, yielding satisfactorily high titers of cellulase and xylanase. Noteworthily, the approach adopted by this study offers an alternative avenue to valorizing agriculture biomass, in conjunction to sustainably produce cellulose-acting enzymes to catalyse biofuel and platform chemical productions.

Optimization of Cultivation Conditions of Lingzhi or Reishi Medicinal Mushroom, Ganoderma lucidum (Agaricomycetes) for the Highest Antioxidant Activity and Antioxidant Content.

Ganoderma lucidum is a famous medicinal mushroom that is rich in antioxidants. The content of antioxidant components of grains can be effectively improved by G. lucidum as the fermenting strain. Optimization of the solid-state fermentation medium and optimization of the fermentation conditions were studied. The optimal fermentation substrate combination of G. lucidum TS (GL-TS) was 46.79% buckwheat, 53.21% rice; the optimal fermentation substrate combination of G. lucidum Am (GL-Am) was 4.17% soybean, 95.83% rice. The optimal fermentation conditions of GL-TS and GL-Am were as follows: inoculum amounts of 4.5% and 7.5%, temperatures of 30°C and 32°C, medium moisture content of 70% for both media, material granularities of 0.212-0.355 mm and 0.500-0.710 mm, and optimal fermentation time of 12.0 d and 10.5 d, respectively. Results of the analysis of antioxidant components in the fermentation substrates indicated that the antioxidant components were rich in antioxidant varieties and high in content. The contents of the antioxidant components (triterpenoids, total polyphenols, reducing sugars, anthocyanins, superoxide dismutase, glutathione, vitamin C, and vitamin E) in the full-fermentation substrates were greater than those in the nonfennentation substrates (except for flavonoids in the full-fermentation substrates, which were less than in the nonfennentation substrates). Glutathione was the major antioxidant component in the fermentation substrates, and the glutathione content was the highest. Therefore, the fermentation substrates of G. lucidum can be used to make antioxidant foods. This research contributes to the foundation for developing antioxidant foods based on G. lucidum.

Fermentative production of soluble phosphorus fertilizer using paddy straw: an alternate to biomass burning

To mitigate environmental impacts caused by illegal burning of paddy straw or stubble in the open fields, an alternate and economical technology for microbial degradation of lignocellulosic biomass and production of soluble phosphorus fertilizer was explored. Low-grade Mussoorie rock phosphate and Udaipur rock phosphate supplemented paddy straw was exploited as solid-state fermentation medium for the fungal-mediated release of soluble phosphorus by phosphate dissolving and cellulase producing strains of Aspergillus niger (ITCC 6719) and Aspergillus awamori (F18). Optimization of process parameters revealed that elemental composition of rock phosphate and its dose are important to affect the per cent yield of soluble phosphorus. Addition of ammonium sulphate or ammonium nitrate or urea to rock phosphate supplemented paddy straw inhibited the release of soluble phosphorus. Contrarily, adding 10% wheat bran (w/w) into paddy straw-rock phosphate mixture and its subsequent fungal inoculation at 10% (v/w) resulted in maximum solubilization (37–38%) of rock phosphate on 21st day of incubation. The fermented extract of this mixture also recorded the highest cellulase activity titre (76.32 IU ml−1) after 3 weeks of fermentation. Soil–plant interaction studies with wheat crop revealed that application of this fermented mixture to soil not only improved the plant biomass but also increased the soil available phosphorus content by ~ twofold, compared to treatments receiving recommended chemical phosphorus. Bio-processing of rock phosphate using wheat bran-amended paddy straw as fermentation substrate can provide an economical and alternate soluble fertilizer for enhanced crop phosphorus nutrition.

Optimization of Solid-state Fermentation Process and Development of Biocontrol Agent Based on Cassava Residue from Streptomyces Microflavus

In this article, solid-state fermentation of low-cost Streptomyces microflavus is studied by using cassava residue, rice husk and other agricultural solid waste resources as the substrate to prepare biopharmaceuticals [1]. The experiment results showed that the Streptomyces microflavus’ optimum solid-state fermentation medium and conditions includes the following components: cassava residue 89.85%, rice husk 10%, KH2PO4 0.05%, NaCl 0.05%, MgSO4 0.05%. The fermentation temperature is controlled at about 30 °C, the initial water content is around 50%, initial pH is 6.6-7, the material thickness is 5cm, the inoculation amount is 7.5%, the cultivation time is 4 days, and the spore yield is 4.8*109 cfu/g. The survival rate of Streptomyces microflavus’ spores is 75%, which compared with blank conditions increased by 30% after low temperature vacuum drying. The work of this paper provides some theoretical guidance for the large-scale industrial production of Streptomyces, which has valuable application in agricultural field.

One-pot strategy for on-site enzyme production, biomass hydrolysis, and ethanol production using the whole solid-state fermentation medium of mixed filamentous fungi.

The efficient use of renewable lignocellulosic feedstocks to obtain biofuels and other bioproducts is a key requirement for a sustainable biobased economy. This requires novel and effective strategies to reduce the cost contribution of the cellulolytic enzymatic cocktails needed to convert the carbohydrates into simple sugars, in order to make large-scale commercial processes economically competitive. Here, we propose the use of the whole solid-state fermentation (SSF) medium of mixed filamentous fungi as an integrated one-pot strategy for on-site enzyme production, biomass hydrolysis, and ethanol production. Ten different individual and mixed cultivations of commonly used industrial filamentous fungi (Aspergillus niger, Aspergillus oryzae, Trichoderma harzianum, and Trichoderma reesei) were performed under SSF and the whole media (without the extraction step) were used in the hydrolysis of pretreated sugarcane bagasse. The cocultivation of T. reesei with A. oryzae increased the amount of glucose released by around 50%, compared with individual cultivations. The release of glucose and reducing sugars achieved using the whole SSF medium was around 3-fold higher than obtained with the enzyme extract. The addition of soybean protein (0.5% w/w) during the hydrolysis reaction further significantly improved the saccharification performance by blocking the lignin and avoiding unproductive adsorption of enzymes. The results of the alcoholic fermentation validated the overall integrated process, with a volumetric ethanol productivity of 4.77 g/L.h, representing 83.5% of the theoretical yield. These findings demonstrate the feasibility of the proposed one-pot integrated strategy using the whole SSF medium of mixed filamentous fungi for on-site enzymes production, biomass hydrolysis, and ethanol production. © 2018 American Institute of Chemical Engineers Biotechnol. Prog., 34:671-680, 2018.

Valorization of Corn-Cob by Fungal Isolates for Production of Xylanase in Submerged and Solid State Fermentation Media and Potential Biotechnological Applications

The increasing awareness of importance of xylanases in various industrial processes has led to intensive research in effective production of xylanases. In this study, eight fungal strains were screened for the production of xylanases in submerged (SmF) and solid state fermentations (SSF) in corncob-based media. Positive results of reddish orange halo-zones of hydrolysis were obtained for qualitative screening. In SmF, xylanase activity from Aspergillus fumigatus SD5A yielded highest activity (50.55 U/ml) in 168 h, while Aspergillus flavus SD4A, A. fumigatus L1, Fusarium solani SD3C, Aspergillus niger L3, Trichoderma longibrachiatum L2, Botryodiplodia sp. L5 and A. flavus L4, showed xylanase activities ranging from 10.38 to 44.81 U/ml. In SSF, xylanase activities ranged from 12.30 to 48.63 U/g in 120 h, with the highest activity obtained from A. fumigatus L1. Optimum temperatures for xylanases obtained in SmF ranged from 55 to 70 °C, while that of SSF ranged from 50 to 70 °C. Also, the optimum pH for xylanases obtained in both SmF and SSF ranged from 5.0 to 7.0. All the fungi did not produce aflatoxin on neutral red desiccated coconut agar. The fungal xylanases improved dough rising of bread and clarification of orange juice by 1.87–2.2-folds and 58.12–74.22% respectively. The results reported here showed that the range of characteristics exhibited by the xylanases could make them widely applicable in various industries, and also an important way for the valorization of agricultural waste.

Optimization of naringinase production by Rhizophus stolonifer in solid state fermentation media using paddy husk as support

The palmyrah (Borassus flabellifer L) tree represents a major socio economic factor in tropics. The economic value of the tree is reduced by fruit pulp, due to the bitter compound present in the fruit pulp but it can be hydrolyzed by the usage of naringinase enzyme. Hence this enzyme plays a key role in the food industry and pharmaceuticals for its debittering nature. Some microbes like bacteria and fungiare involved in the natural production of cost effective naringinase. The aim of this work was to optimize the cultivation conditions and the media to produce naringinase by solid state fermentation of Rhizophus stolonifer, using paddy husk as the support. The highest enzyme activity was obtained on the 7 th day of incubation. Highest naringinase enzyme activity (57.97U/g DM) was obtained on the 7 th day of incubation and after that activity started to decline. The enzyme activity (212.885U/g DM) obtained with 0.75% naringin concentration was significantly higher than that of other naringin concentrations tested. When the regular medium (0.5% glucose) was replaced with (w/v) 1.5% glucose and 1.5% sucrose, the enzyme activity obtained with 1.5% of glucose (484.96U/g DM) was significantly higher than that of 1.5% sucrose (238.88U/g DM). When naringinase activity was tested with different glucose concentrations, activity obtained with 1.5% of glucose concentration was significantly higher than that of other concentrations. Among the nitrogen sources tested, when 0.5 % ammonium nitrate was used significantly higher naringinase was produced by Rhizophus stolonifer than any other sources and their concentrations. The cost to produce 1073.97U/g DM was reduced by 20.15% when conditions and media composition are optimized when compared to the basal medium(57.97U/g DM). Therefore when naringinase was produced by Rhizophus stolonifer under optimized condition, the production cost was marginally reduced.

Optimization of naringinase production from Aspergillus flavus in solid state fermentation media using citrus peel as support

Optimization of naringinase production from Aspergillus flavus in solid state fermentation media using citrus peel as support

Effect of Solid State Fermentation Medium Optimization on Pleurotus ostreatus Laccase Production.

The objective of this work was to increase laccase production by Pleurotus ostreatus PLAB through culture medium optimization using solid state culture conditions. Increased laccase activity was obtained through design of experiments (DOE) using the Taguchi orthogonal array (OA). Seven factors, viz. lignocellulose, glucose, yeast extract, peptone, KH(2)PO(4), MgSO(4) 7H(2)O and MnSO(4) H(2)O at three levels and pH at two levels. OA layout of L18 (2(1) x 3(7)) was selected for the proposed experimental design using Minitab 17 software. Data analysis showed that lignocellulose (20 %) and glucose (10 g L1) had positive effect, whereas KH(2)PO(4), MgSO(4)∙7H(2)O and MnSO(4)∙H(2)O did not have significant effect on laccase production. Taguchi OA analysis showed that pH 6, lignocellulose 20 %, glucose 10 g L(-1), yeast extract 6 g L(-1), peptone 15 g L(-1), KH(2)PO(4) 3 g L1, MgSO(4)∙7H(2)O 0.5 g L(-1) and MnSO(4)∙H(2)O 0.1 g L-1 were the optimal conditions to maximize laccase production. The model predicted a 30.37 U g(-1) dry wt., which agreed with the experimentally obtained laccase activity 29.15 U g(-1) dry wt. at optimal conditions.