Solid State Fermentation Technique Research Articles

Bacillus cereus-mediated biofermentation of Sardine offal waste: A novel approach to enhance nutritional value by Response Surface Methodology optimization

The rising protein demand in the aquaculture sector has significantly impacted fishmeal supply and pricing. Excessive use of fishmeal can lead to environmental issues and negatively impact marine biodiversity and human food security. Consequently, finding alternative fishmeal in aquaculture is crucial for economic and environmental sustainability. The present study aimed to determine how Bacillus cereus (MT355408) could enhance nutritional value of Sardine fish waste, which could replace fish meal in the market. Solid-state fermentation (SSF) represents a biotechnological method that utilizes microbes to convert discarded fish byproducts into valuable products. The bacterial ability to produce enzymes was studied and optimised for its maximum production to be used as an inoculum for the SSF technique. Different prebiotic sources were also studied for better upliftment of bacteria in the solid-state surface. A single-factor analysis was conducted to investigate the influence of varying prebiotic concentrations, inoculum quantity, and fermentation duration on protein breakdown. After studying the single-factor tests, a further response surface model was employed for better yield. The results indicated that the highest protein yield could be achieved with a fermentation time of 132.893 hours, a prebiotic quantity of 25%, and an inoculum quantity of 5.3%. The study's findings also affirmed that the model was vital in enhancing the crude protein content during fermentation. In conclusion, the model's results contribute valuable insights into fermentation processes, offering practical implications for enhancing protein content and digestibility in similar contexts.

Investigation of optimal parameters for aspartic protease production from Aspergillus terreus using solid-state fermentation

The current study presents extracellular Aspartic protease production using low-cost agro-industrial waste with the indigenously isolated novel strain Aspergillus terreus, and parameters that largely affect enzyme production, namely fermentation time, pH, moistening solution, temperature, inoculum volume, and different solutions, were utilized for enzyme extraction. The isolated fungus was identified as A. terreus (registered as A. terreus SFH5 in the gene bank) by phenotypic and molecular characterization, showed the highest aspartic protease activity of 258.6 units/mL and 272.2 units/mg using a solid-state fermentation technique during screening, and was further used for media component screening and optimization studies. The study employed wheat bran as the preferred production medium and casein as the nitrogen source. The fermentation process was conducted at a temperature of 30°C and a pH of 5. The moistening solution to fermentation medium ratio was set at 3:1, while an inoculum volume of 2 mL (containing 1 × 106 spores/10 g solid) was used. Distilled water was selected as the most effective solution for extracting the enzyme. It has been discovered that the locally isolated novel strain of A. terreus, SFH5, can efficiently produce a substantial amount of aspartic protease by utilizing agro-industrial waste. This makes it a viable candidate for large-scale optimized production of the enzyme to satisfy industrial requirements.

Optimization of nutrient media for glucoamylase production by Plackett-Burman design using Aspergillus niger

Background: Glucoamylase is an important enzyme produced by various bacterial and fungal species as an intracellular or extra cellular enzyme. It is used to treat gastrointestinal issues, autoimmune diseases, inflammation, psoriasis, allergies, eczema, emphysema and asthma, and thus, supplements are often included in complexes for digestive disorders and also applications in different industries. Methods: Natural ingredients are screened for glucoamylase production by stationary culture of solid-state fermentation technique and Plackett-Burman design microorganism used Aspergillus niger. Eight nutrient medias are designed and from this glucoamylase isolated from the medium by centrifugation at 1500 rpm and assayed by spectrophotometric method. Results: high glucoamylase levels are found in nutrient media VI with optimized physical conditions like percentage inoculum- 2%, pH- 6, incubation temperature- 400C upon incubation for 4 days. Conclusions: High amount of glucoamylase is produced in the media VI due to the presence of high amounts of sucrose and optimum concentration of potato, peptone, wheat bran and yeast extract.

Enhanced Production of Bacillus Thuringiensis Israelensis using Solid State Fermentation Technique

Vectors play an important role in disease transmission, globally. Despite various advancements in vector management, mosquitoes are still prime vectors of dreadful diseases which influences human health and economy as well. Bacillus thuringiensis israelensis (Bti) is a major bacterium that produces δ-endotoxin, which can kill the certain strains of mosquito larvae. Bti based biopesticides can be used as an alternative technique to control insects. Biopesticides derived from Bti are the most prominent biological agents for selective control of insect pests. In this study we aim to produce Bti using different cost-effective medias based on the fruit, pulses and sea food waste and other such materials using solid state fermentation techniques (SSF). SSF has been described as the process that takes place in solid matrix in the absence or near absence of water, and the substrate requires less moisture to support the growth and metabolic activity of organisms. Here, in the present study we use different fruit wastes as carbon sources and other wastes as nitrogen source to optimize cost effective and efficient media for the growth and sporulation of Bti. Fruit juices of rotten fruits like pineapple, grapes, watermelon etc were used as a substrate for the production of Bti. Nitrogenous supplements like prawn peel powder, peanut meal extract, poultry manure was also used for the overproduction of Bti. Finally, the larvicidal efficiency of the novel media was also determined. This method was found to be cost effective and is functional also, and it can solve the problems caused by fruit waste accumulation. It can also reduce the problems inflicted by disease carrying vectors like mosquitoes.

Influence of Different Extraction Methods on the Changes in Bioactive Compound Composition and Antioxidant Properties of Solid-State Fermented Coffee Husk Extracts.

In brewing coffee, a huge amount of food waste is generated; that waste, coffee husks in particular, should be comprehensively exploited. They offer a rich source of bioactive compounds such as caffeine, chlorogenic acid, and trigonelline. The aim of this study was to investigate the effects of extraction methods on the bioactive compounds and antioxidant activity of such waste. Coffee husks in this study were fermented with S. cerevisiae based on a solid-state fermentation technique. The study method included ethanolic or water extraction with varied controllable factors, i.e., temperature (60, 100°C) and extraction technique. Bioactive contents were investigated with the Folin-Ciocalteu assay and 1H-NMR spectroscopy. The antioxidant activity was investigated with DPPH and FRAP assays. Results show that yields were the highest in the extract of fermented coffee husks at 100°C. The highest levels of bioactive contents (total trigonelline content at 3.59% and antioxidant activity at 23.35% (DPPH) and 25.9% (FRAP)) were found in the ethanolic extract of fermented coffee husks at 60°C. The bioactive content and bioactivity, including antioxidant activity, depended on different raw materials, preparation methods, and extraction conditions. This study illustrates the potential for using food waste such as coffee husks as a sustainable source of bioactive compounds or bioactive extracts.

Screening of Chitinolytic Microfungi and Optimization of Parameters for Hyperproduction of Chitinase Through Solid-State Fermentation Technique.

This study is intended for the production of chitinase enzyme from locally isolated fungal strains. Out of 10 isolated fungal strains from district Gujrat, Punjab, Pakistan, Aspergillus terreus SB3 (accession number ON738571) was found with maximum chitinolytic potential (80.8 U/mL/min). By applying central composite design (CCD) through response surface methodology (RSM) under solid-state fermentation (SSF), eight nutritional and physical parameters were optimized. Among these, temperature, substrate concentration, and pH were found as significant factors toward chitinase production in the first phase. Moisture and nitrogen source were found as significant factors during second phase of chitinase production. The effect of incubation period, inoculum size, and magnesium source was observed as non-significant. The chitinase activity was successfully enhanced more than 2 folds up to 198.5 U/mL/min at optimized conditions of 35°C temperature, 4.5 pH, 20g substrate concentration, 4-day incubation period, 55% moisture content, 4.5mL inoculum size, 0.25g ammonium sulfate, and 0.30g magnesium sulfate using RSM design. It was also found that Ganoderma lucidum (bracket fungus) has more potential to be used for the production of chitinase compared to fish scales. The present study exhibited Aspergillus terreus SB3 (ON738571) as a potential indigenous strain capable for hyperproduction of chitinase through cheap fermentation technology that might be employed for the eradication of chitin-based sea waste to remove the marine pollution.

Studies on red-pigment production by Talaromyces atroroseus TRP-NRC mutant II from wheat bran via solid-state fermentation

Background Recently, the need of finding eco-friendly and less-hazardous pigments focused on an important alternative to harmful synthetic dyes. High productivity of various pigments from microorganisms, their rapid growth throughout the year, stability, and solubility of their pigments provide them advantages more than pigments produced from other natural sources.Objective The objective of this study is to improve red-pigment production from local isolated fungus Talaromyces atroroseus TRP-NRC on an inexpensive substrate (wheat bran) under solid-state fermentation system by using different mutants. Then, comparing between pigment released from fungi after mutation by different mutants, comparing the efficiency of different solvents for the extraction of red biopigments under different conditions, and then extraction of pigment and studying its structure.Materials and methods A novel locally non-mycotoxin-producing fungus T. atroroseus TRP-NRC was treated with γ-ray radiation followed by subjecting to ultraviolet rays and grown on wheat bran as a complete medium via solid-state fermentation technique. Different solvents, including water, ethanol, methanol, and acetone, were applied to extract pigment from dried fermented wheat bran. The effect of pH, temperature, and contact time on yield of pigment extraction was studied. Stability of extracted pigment to heat, autoclaving, and ultraviolet rays was studied. Antimicrobial activity of extracted pigment was studied. The extracted sample was subjected to high-performance liquid-chromatography analysis and gas chromatography–mass spectrometry analysis. Statistical analyses were performed using SPSS program at P value less than 0.05.Results and conclusion The mutant fungus (I) by gamma radiation achieved 30% increase in red pigment compared with the wild type. The mutant fungus (I) was subjected to ultraviolet rays, mutant (II) added 22% increase in pigment production compared with mutant obtained by gamma radiation. About 70% v/v of methanol, ethanol, and acetone were more efficient for extracting pigment with an advantage of 70% v/v acetone. The yield of pigment extraction was affected by pH, temperature, and contact time, and was at pH 6.5 at 50°C after 16 h. The produced pigment appeared to be heat-stable when subjected to heat from 30 to 80°C for 6 h. The pigment was also stable when autoclaved at 121°C for 15 min. The pigment was stable when subjected to ultraviolet rays for 6 h. The extracted pigment showed antibacterial activity against Bacillus subtilis (Gram-positive) and Escherichia coli (Gram-negative). Gas chromatography–mass spectrometry analysis revealed that eighteen compounds were identified in the acetone extract of pigment. In general, the prevailing two compounds of fermented wheat bran by T. atroroseus TRP-NRC mutant-II extract were 9, octadenoic acid (43.72) and 1,1′-bicyclopropyl-2-octanoic acid, 2′-hexyl-, methyl ester 43.72%.

Recent Advances and Technologies in Chitinase Production Under Solid-State Fermentation

ABSTRACT: Our target is to evaluate recent literature on chitinase production from different sources via solid-state fermentation and to analyze several strategies to improve chitinase production via solid-state fermentation. Plant pathogen biocontrol, sequential transformation of chitin into bioactive molecules such as chito-oligosaccharides and N-acetylglucosamine, protoplast synthesis from filamentous fungi, and single-cell protein production are some of the applications for chitinase. Despite their enormous biological importance, chitinases have received little commercial importance due to the smaller percentage of microbes with high efficiencies, the enzymes' decreased activity and consistency, and the cost of production. Solid-state fermentation (SSF) is less expensive, requires fewer vessels, uses less water, requires fewer wastewater treatments, produces a greater product yield, has a lower risk of bacterial contamination, and requires less energy expenditure. Despite its higher productivity and lower cost, the SSF technique is now mostly limited to lab scales. Furthermore, the crude SSF products can be used as an enzyme source for biotransformation. There are many findings on different microorganisms that produce chitinase by SSF. So it is very critical to isolate new organisms for such production. So we assessed the traditional approach to medium optimization, which focuses on changing one factor at a time while leaving the others constant, and statistical optimization techniques such as response surface methodology (RSM), artificial neural networks (ANNs), and genetic algorithms (GA).

A probiotic based product using multi-strain Bacillus species and predictive models for shrimp growth following probiotic intervention

Probiotic bacteria in aquaculture found to have significant effect on health of shrimp and growth by changing the microbial composition of water. The primary objective of the study is to develop a probiotic based product to improve the yield of shrimp by using multi-strain Bacillus species. Towards this, various Bacillus strains, namely, B. subtilis, Bacillus clausii, B. cereus, B. Megaterium, B. pumilus and Bacillus polymyxa were collected and confirmed the strains through biochemical tests in subculture. Further, it is found that all the six strains exhibited good antifungal, antibacterial, antagonistic and enzyme activities. Multi-strain probiotic product as feed for the growth of shrimp was prepared by using the solid state fermentation technique and quality check was done to make sure no contamination. After the product development, the efficacy of the product has been tested by conducting field studies. The parameters such as (i) temperature (ii) pH (iii) dissolved oxygen (iv) total ammonia nitrogen and (v) shrimp weight & (vi) length were investigated for about 120 days and measurements were taken at every 5-day interval. The average initial weight and length of shrimp is 4.2 ± 0.2 g and 0.8 ± 0.1 cm respectively. The average values obtained for 120 days include (i) Temperature (°C): Control = 28 ± 0.3; Treated = 28 ± 0.15 (ii) pH: Control = 8 ± 0.19; Treated = 8 ± 0.12 (iii) Dissolved oxygen (ppm): Control = 5 ± 0.23, Treated = 5 ± 0.21 (iv) Total ammonia nitrogen (ppm): Control = 2 ± 0.2; Treated = 0.8 ± 0.01 (v) Shrimp weight (gm): Control = 16 ± 0.21; Treated = 22 ± 0.14 (vi) Length (cm): Control = 6 ± 0.14; Treated = 8 ± 0.26. The average survival rate was found to be 88.67 ± 1.15% in probiotics ponds and 70.00 ± 3.0% in controlled ponds. From the overall study, it is observed that the weight and length of shrimp has been increased significantly up to sixty days compared to control environment. Two-way ANOVA has been performed to understand the interdependent relation between the input and output variables. Advanced statistical models were developed by using the concepts of Artificial neural network, Multivariate adaptive regression splines and Relevance vector machine to predict the shrimp weight and length. The predicted shrimp weight and shrimp length is found to be in close agreement with those of the corresponding experimental observations. The models are found to be robust, reliable and efficient.

Beauveria bassiana Konidilerinin Katı Faz Fermantasyonu ile Kitlesel Üretimi için Bazı Tahılların İncelenmesi

This study was conducted to test five substrates (whole rice, broken rice, dovme, wheat and burghul) for the mass production of Beauveria bassiana isolate 5-4, known to be affective against stored-cereal pests. A solid-state fermentation technique was used, and amount of product, number of conidia, germination, hydrophobicity and thermotolerance of conidia, and their virulence on Rhyzopertha dominica adults were used to evaluate the success of substrates. For production, 100 g of a substrate was used in a polypropylene bag. After sterilization and inoculation, the bags were sealed and incubated for 14 days at 25ºC. Hydrophobicity was assessed using the aqueous-solvent partitioning method with PM buffer, and liquid paraffin as two phases. Thermotolerance tests were conducted by exposing conidia to 35, 40 and 45°C for 15, 30 and 60 minutes. In virulence test, adults were released into 40 gr wheat mixed with conidia and kept at 25oC and 65% relative humidity in darkness for 14 days. The highest amount of product was obtained by using whole rice (4.10g/bag), followed by broken rice, wheat, dövme and burghul. The highest number of conidia was achieved using broken rice (10.24x1010conidia/g) and whole rice (9.62x1010conidia/g). The germination rates of conidia did not vary significantly. Significantly higher hydrophobicity rate was obtained using wheat (88.73%). The conidia from burghul and wheat showed higher thermotolerance than those from other substrates. The conidia obtained from whole rice and broken rice caused 80.3% and 72.0% mortalities, respectively, significantly higher than the others. Rice was found to be a better choice for this isolate as the ultimate purpose is to suppress pest populations, with awareness of its shortcomings. It was found crucial to test all important characteristics of produced conidia together for assessment of substrates.

Pectinolytic activity of aspergillus niger and Aspergillus flavus grown on grapefruit (citrus Parasidis) peel in solid state fermentation

The present study was aimed at studying pectinolytic activity of resident fungi isolated from decomposing grapefruit (Citrus parasidis) peels in solid state fermentation. Grape fruit peel was subjected to natural fermentation and the fermenting fungi were isolated, characterized and identified using standard microbiological methods. The isolated fungi were in turn used for fermentation to determine their pectinolytic activity through solid state fermentation technique. Culture parameters such as incubation period, temperature, moisture content and addition of salts supplements were optimized during the research for five days. The identified fungi were Aspergillus Niger and Aspergillus flavus. The peak of pectinolytic activity was at day three of fermentation when the highest pectinase activity of 13.32 μmol/mg/min was recorded for A. Niger and 11.32 μmol/mg/min for A. flavus. Optimum temperature and pH for pectinase activity by A. Niger and A. flavus was at 40 0C and pH 7.5 and 7.7 respectively. The use of salt supplemented substrate did not alter enzyme activity. In conclusion, the isolated fungi could be promising organisms for pectinolytic enzyme production on grape peel as substrate.
 Keywords: Grapefruit, Pectinolytic Activity, Fungi, Fermentation, Aspergillus

Water Extract of Mixed Mushroom Mycelia Grown on a Solid Barley Medium Is Protective against Experimental Focal Cerebral Ischemia.

Although the individual consumption of medicinal mushrooms, including Phellinus linteus (PL), Ganoderma lucidum (GL), and Inonotus obliquus (IO), is known to be neuroprotective, the associated mechanisms underlying their therapeutic synergism on focal cerebral ischemia (fCI) have yet to be elucidated. This study aimed to demonstrate the neuroprotective effects of mixed mushroom mycelia (MMM) against experimental fCI. The water-fractions, ethanolic-fractions, and ethyl acetate-fractions of the MMM (PL, GL, and IO) grown in a barley medium using solid-state fermentation techniques were prepared and their protective effects against glutamate-induced excitotoxicity were compared in PC-12 cells. After the identification of the water extracts of MMM (wMMM) as the most suitable form, which possessed the lowest toxicity and highest efficacy, further analyses for evaluating the anti-apoptotic effects of wMMM, including Hoechst 33258-based nuclear staining, fluorescence-activated cell sorting, and reactive oxygen species (ROS) detection assays, were performed. Rats were subjected to a 90 min middle cerebral artery occlusion and reperfusion, after which a wMMM treatment resulted in significant dose-dependent improvements across a number of parameters. Furthermore, measurements of intracellular ROS and levels of antioxidant enzymes revealed a wMMM-mediated ROS attenuation and antioxidant enzyme upregulation. We suggest that wMMM is neuroprotective against fCI through its anti-apoptotic and anti-oxidative effects.

Cellulases and animal feed production by solid-state fermentation by Aspergillus fumigatus NRCF-122 mutant

A high cellulase-producing fungus was isolated from agricultural waste compost, purified, identified genetically as Aspergillus fumigatus NRCF-122 (accession no. MT318341), and improved by UV-irradiation for cellulase production (named as A. fumigatus mutant-17). Optimal cellulase production conditions were studied using sugar beet pulp “SBP” as the substrate of solid-state fermentation technique. The optimal conditions were: initial moisture content ratio (1:2 w/v), incubation temperature (30°C), initial pH of solid culture (10), incubation period (4 days), aeration area (1:100 ratio ((1%)), SBP substrate weight : flask volume of moistened SBP in a 250 mL Erlenmeyer flask, fungal inoculum (seeding) culture age (3 days) and inoculum size (20%, v/w). Studies were also involved the effect of different nitrogen sources where urea is the best nitrogen source for cellulase production. Concerning the application of bioethanol production from yeast, using rice straw cellulose as a source of fermentable reducing sugars), the lingo-cellulosic waste rice straw was first pretreated (with NaOH 1.5%) to reduce crystallinity of cellulose & removing lignin and other inhibitors, enhancing the subsequent process (saccharification) of rice straw cellulose. Then, its cellulose was saccharified enzymatically by cellulases (produced from SBP as substrate (under SSF condition) as substrate under the optimum conditions) resulting in reducing sugars. one of the largest livestock production operating costs is the feed bill. In our study we evaluated the resulted crude protein content of the fermented SBP and the results declared that, the total digest nutrient (TDN) and gross energy performance were increased, where as crude fiber, acid detergent fiber ADF & neutral detergent fiber NDF were decreased, thereby upgrading the feed quality of biologically treated SBP.

The Chemical Fermentation Process Properties, Bioactive Compounds, and Health Benefits of Fruit Vinegars in Pilot-Scale in Thailand

Vinegar is a liquid product produced from alcoholic and acetous fermentation. Vinegar contains acetic acid and bioactive compounds, which are brewed by liquid-state and solid-state fermentation techniques. This study reviews chemical fermentation process properties, bioactive compounds, and health benefits of fruit vinegars in Thailand. Chemical properties are the alcohol percentage and acetic acid percentage of vinegar. Bioactive compounds include antioxidant activity and total phenolic content, which have the role of antioxidative activity, blood pressure and glucose control, and anti-tumor. However, further studies are needed to find the new fruit raw materials to produce fruit vinegar which have more bioactive compound and more good taste.

Filamentous fungi isolated from Tunisian olive mill wastes: use of solid-state fermentation for enzyme production

Olive mill wastewaters and olive cake are effluents generated during olive oil production process. They represent a major disposal and potentially severe pollution problem for the industry, also promising source of substances of high value. The aim of this study is the valorization of olive mill wastes (OMWW, olive cake, olive twigs and leaves) to produce enzymes with high industrial and biotechnological potential, by the solid-state fermentation technique (SSF), from isolated fungi present in olive mill wastewater and olive cake. A total of 47 strains were isolated and purified from these two residues. The metabolic potential of isolated strains was study by testing the hydrolytic enzymes activities of lipase, protease, amylase, cellulase, invertase, phytase and tannase on agar plate media containing different substrate. The monitoring of SSF has shown that the metabolic activity of these strains is extremely rapid using this technique. Our fungi collection contains a diversity of strains capable to producing a variety of enzymes of biotechnological interest.

Bio-active compounds, their antioxidant activities, and the physicochemical and pasting properties of both pigmented and non-pigmented fermented de-husked rice flour

The aim of this study was to determine the effect of both the Solid State Fermentation (SSF) technique and the use of <i>Rhizopus oligosporus</i> on the physicochemical changes of fermented de-husked rice flour. Three varieties of de-husked rice, i.e., Mentik Wangi Susu (non-pigmented), red Cempo Merah, and black Jowo Melik (pigmented) were fermented using <i>Rhizopus oligosporus.</i> Fermentation was performed at room temperature with a fermentation time of 0, 24, 48, and 72 hours. The analyzed parameters were proximate composition, bio-active compounds, and pasting profile. The results showed an increase in flour pasting profile, ash, protein, and fat content after the fermentation. The total availability of the total phenolic content (TPC) and antioxidant capacity were also increased. The highest TPC (0.37 mg GAE/g) and antioxidant capacity (1.43 mg TEAC/g) were obtained in the Jowo Melik variety at 72 hours of fermentation. In contrast, anthocyanin and carbohydrate contents decreased as fermentation time increased. The highest anthocyanin content of 0.53 mg/g (after 24-hour fermentation) was obtained in the Jowo Melik variety. In conclusion, 72-hour-fermented black rice flour (Jowo Melik) has a higher potential to be developed as a functional food.

The energy potential of soft rush (Juncus effusus L.) in different conversion routes

BackgroundRushes are prominent wetland plants that are well adapted to conditions of waterlogging. Tall rushes like soft rush (Juncus effusus L.) tend to dominate the vegetation and offer a great biomass potential. Removing rush biomass is often necessary to enhance various ecosystem services of wetlands. There is an urgent need for sustainable use of the removed biomass apart from expensive composting ore useless landfill.MethodsWe investigated three alternative energy utilisation routes for soft rush biomass and evaluated their energetic potential: biomethanisation via wet fermentation technique (a), biomethanisation via solid-state fermentation technique (b) and combustion (c). Batch experiments (a), experimental fermenters (b), and thermo-calorimetric equipment (c) were used to measure energy output per unit rush biomass input.ResultsThe wet fermentation technique had significantly higher biogas yields than solid-state fermentation (399 LN kg−1 oDM compared to 258 LN kg−1 oDM). These yields constitute 59 and 43%, respectively, of the biogas potential of maize silage as a reference. Solid-state fermentation technique needs longer retention time compared to wet co-digestion to earn comparable methane yields. Soft rush biomass shows high heating values (15.06 MJ kg FMw15−1) compared to other herbaceous solid fuels.ConclusionsLow costs for substrate production make energetic utilisation of Juncus effusus an interesting alternative, if short distances between fields and biomass conversion plant can be realised. All investigated conversion routes appear promising, provided that the substrate specifics are considered in the design of the conversion technique. Besides the size of the rush dominated area and the distribution of these areas in the landscape, the investment costs and the subsidies for the conversion plant play a pivotal role in the selection of the preferred conversion path.

White rot fungus Pleurotus pulmonarius enhanced bioremediation of highly PCDD/F-contaminated field soil via solid state fermentation

This study was performed to evaluate the use of white rot fungus, Pleurotus pulmonarius, to treat polychlorinated dibenzo-p-dioxins and furans (PCDD/Fs) in contaminated soil using solid state fermentation (SSF). The soil was collected from a long-closed pentachlorophenol plant in southern Taiwan. The non-sterilized soil with a total PCDD/F concentration of 14,000 ± 2400 ng I-TEQ kg−1 was mixed directly with the solid fungal inocula at dry w/w ratio of 1:1.4 (ratio-adjusted test) and incubated at 26 ± 2 °C in a controlled environment. The highest PCDD/F decomposition was observed during the mycelium colonization. Pearson correlation coefficient (r) studied during this period (35 days) indicated that laccase had no significant correlation (r = −0.53), while manganese peroxidase had a strong positive correlation (r = 0.88) with PCDD/F decomposition efficiency. After 72 days, the more toxic congeners, tetra- and penta-CDD/Fs were removed to non-detectable levels. Meanwhile, the removal efficiencies of hexa-, hepta-, and octa-CDD/Fs were >80%, >97%, and >90%, respectively. The simultaneous degradation of low and high chlorinated DD/Fs suggested that overall removal was nonspecific. The overall PCDD/F removal was 96%, and the residual concentration (276 ng I-TEQ kg−1) was below the regulatory control limit (1000 ng I-TEQ kg−1). In conclusion, this study shows that P. pulmonarius via SSF can successfully remediate the PCDD/F-contaminated field soil. Furthermore, this SSF technique overcame the well-known intractability of PCDD/F biodegradation in non-sterilized soil, making it promising for actual field application.

Production of dextranase by aspergillus fumigatus NRC-F103 and its application in cane juice treatment and enhancing ethanol production from sugarcane molasses

Background and objectives One of the important applications of dextranase enzyme is preventing dextran accumulation in sugarcane juice as well as, consequently, for enhancing the resultant fermentable reducing sugars and ethanol yield in the fermentation of sugarcane molasses by yeasts. Materials and methods Different materials and methods were used for fungal strains [screening, mutation ultraviolet (UV), inoculum preparation, cultivation type ‘solid-state fermentation,’, culture substrates], dextranase (production, assay, soluble protein determination), purification, characterization, application in ethanol production by fermentation from sugarcane molasses, dextran estimation, and determination of reducing sugars. Results and conclusion Six fungal strains (namely Aspergillus oryzae FK-923, Aspergillus niger F-93, A. niger F-258, Aspergillus awamori NRC-F18, Aspergillus fumigatus NRC-F103, and Trichoderma viride NRC-F107) were screened on sorghum, sugar beet pulp, wheat bran, and orange peels using the solid-state fermentation technique to produce dextranase enzyme. The fungus A. fumigatus NRC-F103 cultivated on orange peels showed promising enzyme yield than other tested fungal strains. Then, optimization of culture conditions for dextranase production was carried out. Moisture content, initial pH value, incubation temperature, and incubation period were optimized to be 2 : 1 (v/w), 5.0, 35°C and 96 h, respectively. Five inorganic nitrogen sources were trailed at equivalent levels as sole nitrogen in the fermentation medium did not result in any increase in enzyme activity. Subjecting the fungal to UV resulted in a 75% increase in enzyme activity corresponding to the mother strain before subjecting to UV. Under the above conditions, 118 U/g original substrate was obtained. Isopropanol 1 : 1 (v/v) was applied for precipitation enzyme protein, as 32% of total protein involving 68% of total enzyme activity was obtained and specific activity was 42.94 U/mg protein compared with 16.4 U/mg protein in the culture supernatant. A study on obtained dextranase showed that it has an optimum that pH ranged from 4.5 to 5.5 as well as it gave the highest activity when incubated between 35 and 40°C. Promising results were obtained when the enzyme was applied in cane juice to prevent accumulation of dextran. Enzyme supplementation to diluted sugarcane molasses (26%, w/v) resulted in an increase in reducing sugars by 2.64%. Ethanol was increased by about 2.36% (v/v) in the fermentation medium supplemented with an enzyme compared with the unsupplemented medium and the fermentation efficiency increased from 89 to 92.5%.

Nutrients and bioactive components from vinegar: A fermented and functional food

Abstract Vinegar has been widely used as acidic condiment worldwide for thousands of years. Vinegar contains various nutrients and bioactive components, which are brewed by liquid-state and solid-state fermentation techniques. This review highlights the nutrients and bioactive components in different types of vinegars and their functional properties. Nutrients in vinegar include amino acids, sugars, vitamins, and minerals. The functions of these nutrients were providence energy, regulation of cell metabolism regulation, immunoregulation, antioxidation, anticoagulation and improvement of brain development. In addition, the bioactive components in vinegar include organic acids, polyphenols, melanoidins, and tetramethylpyrazine, which have the functions of antioxidative activity, regulation of lipid metabolism, liver protection, blood pressure and glucose control, anti-fatigue and anti-tumor. However, further studies are needed to explore the novel functional compounds in vinegars and their molecular mechanisms on health benefits in future.