Solid-state fermentation for recovery of carotenoids from tomato waste

Tomato waste is an excellent source of nutrients, micronutrients, and bioactive compounds. Some extraction technologies have been used to recover these pigments for their proven biological activities. In this study, solid-state fermentation with Aspergillus niger GH1 was used as a bioprocess for carotenoid extraction and recovery in tomato waste. The chemical composition was evaluated, in addition to the viability of the tomato waste as a solid-fermentation substrate. The results showed that at 70% humidity, pH 4.0, 30 °C, 1 × 10⁶ spores/g of inoculum concentration, and 36 h of fermentation gave the optimal yield. A biomass/carotenoids ratio of 0.164 mg/L of total carotenoids was realized. The number of carotenoids extracted from tomato waste was improved from 0.062 mg/L from zero hours of fermentation to 0.164 mg/L of total carotenoids after 36 h of fermentation. Solid-state fermentation with Aspergillus niger GH1 was a viable approach to enhance the extraction and recovery of carotenoids.     

Enhanced Oil Recovery by Pre-treatment of Mustard Seeds Using Crude Enzyme Extract Obtained from Mixed-Culture Solid-State Fermentation of Kinnow (Citrus reticulata) Waste and Wheat Bran

Solid-state fermentation (SSF) of kinnow (Citrus reticulata) waste supplemented with wheat bran was used for production of cellulase, protease and pectinase with individual and mixed cultures of Trichoderma reesei and Aspergillus niger. Mustard seeds were pre-treated with crude filtrate extract (CFE) obtained from A. niger and T. reesei independently, and combination of the two cultures, prior to solvent extraction. Mixed-culture fermentation resulted in higher enzyme activity for filter paper cellulase (FPU), carboxymethyl cellulase (CMCase), β-glucosidase, and exoploygalacturonase (exo-PG) in comparison to fermentation with individual cultures. This study indicated that pre-treatment using crude enzyme obtained with mixed cultures enhanced the oil recovery by 11% as compared to control where no enzyme was used. Mustard seeds pre-treated with CFE obtained from mixed cultures having ratio of 2:1:1 for exo-polygalacturonase, FPU, and protease resulted in highest oil recovery. About 7–10% more oil was recovered when mustard seeds were pre-treated with CFE obtained from individual cultures, compared with control. Enzymatic pre-treatment also improved some of the quality attributes of mustard oil. To the best of our knowledge, this is the first study where mixed-culture SSF was attempted to produce enzyme consortium for pre-treatment of mustard seeds for enhanced oil recovery.     

Effect of substrate and fermentation conditions on pectinase and cellulase production by <Emphasis Type="Italic">Aspergillus niger</Emphasis> NCIM 548 in submerged (SmF) and solid state fermentation (SSF)

The present study deals with the optimization of substrate and fermentation conditions for the production of both pectinase and cellulase by Aspergillus niger NCIM 548 under same fermentation conditions in submerged fermentation (SmF) and solid state fementation (SSF) using a central composite face centered design of response surface methodology (RSM). As per statistical design, the optimum conditions for maximum production of pectinase (1.64 U/mL in SmF and 179.83 U/g in SSF) and cellulase (0.36 U/mL in SmF and 10.81 U/g in SSF) were, time 126 h, pH 4.6, and carbon source concentration 65 g/L in SmF and were time 156 h, pH 4.80, and moisture content 65% in SSF. The response surface modeling was applied effectively to optimize the production of both pectinase and cellulase by A. niger under same fermentation conditions to make the process cost-effective in both submerged and solid state fermentation using agro industrial wastes as substrate.     

Production of α‐amylase by Aspergillus oryzae As 3951 in solid state fermentation using spent brewing grains as substrate

BACKGROUND: The optimisation of nutrient levels for the production of α‐amylase by Aspergillus oryzae As 3951 in solid state fermentation (SSF) with spent brewing grains (SBG), an inexpensive substrate and solid support, was carried out using response surface methodology (RSM) based on Plackett–Burman design (PBD) and Box–Behnken design (BBD). RESULTS: In the first optimisation step a PBD was used to evaluate the influences of related factors. Corn steep liquor, CaCl₂ and MgSO₄ were found to be the most compatible supplements to the substrate of SBG and influenced α‐amylase activity positively. In the second step the concentrations of these three nutrients were optimised using a BBD. The final concentrations (g/g dry substrate basis) in the medium optimised with RSM were 1.8% corn steep liquor, 0.22% CaCl₂ and 0.2% MgSO₄ · 7H₂O using SBG as the solid substrate. The average α‐amylase activity reached 6186 U g^?1 dry substrate under the optimised conditions at 30 °C after 96 h. Under the optimised conditions of SSF an approximately 17.5% increase in enzyme yield was observed. CONCLUSION: SBG was found to be a good substrate for the production of α‐amylase by A. oryzae As 3951 under SSF. Copyright © 2007 Society of Chemical Industry     

Fermentation of Allium chinense Bulbs With Lactobacillus plantarum ZDY 2013 Shows Enhanced Biofunctionalities,and Nutritional and Chemical Properties

In this study, fermentation of Allium chinense bulbs was carried out with Lactobacillus plantarum ZDY 2013. A decrease in pH from 6.8 to 3.5 and a stable lactic acid bacteria population were observed during 7‐d fermentation. The total phenolic content increased by 2.7‐fold in the aqueous and ethanol extracts of A. chinense bulbs after fermentation. Antioxidant capacity including 2,2‐diphenyl‐1‐picrylhydrazyl radical‐scavenging effect and reducing power of both extracts was significantly (P < 0.05) improved after fermentation. Antagonistic test against 6 pathogens showed that fermentation significantly (P < 0.05) enhanced the antimicrobial activity in both extracts of fermented bulbs, especially in the ethanol extracts of fermented bulbs against L. monocytogenes. Analysis of the free amino acid (FAA) profile by ion‐exchange chromatography revealed that fermentation significantly (P < 0.05) increased total FAA content. In addition, among 27 kinds of volatile components analyzed by headspace–solid phase microextraction–gas chromatography–tandem mass spectrometry, sulfur‐containing compounds accounted for 65.23%, but decreased to 43.65% after fermentation. Our results suggested that fermentation of A. chinense bulbs with L. plantarum could improve their biofunctionalities, and nutritional and chemical properties.     

The biodiversity and evolution of lactic flora during ripening of the Iranian semisoft Lighvan cheese

Ninety‐five isolated strains of Lactic acid bacteria (LAB) were identified from Lighvan cheese. The LAB evolution showed the dominance of lactococci and lactobacilli in the first stage and substitution of these genera by enterococci at the end of ripening. The most predominant strains were Enterococcus faecium (22.44%), Lactococcus lactis ssp. lactis (20.4%), Lactobacillus plantarum (18.36%) and E. faecalis (14.28%), respectively. Eleven and 51 different carbohydrate fermentation profiles were observed according to API 20 STREP and API 50 CH, respectively. API 20 STREP dendogram showed identical fermentation profiles of some E. faecalis and E. faecium strains, indicating that these strains might be well adapted to the whole cheese manufacture.     

Screening of different agroindustrial by-products for industrial enzymes production by fermentation processes

Agroindustrial by-products are an abundant source of biocompounds that contain valuable nutrients, which are not exploited. In this work, lignocellulosic wastes (LW) were used in submerged fermentation (SmF) and solid-state fermentation (SSF) by Aspergillus niger NRRL3 to obtain valuable enzymes required in industries. SmF using soya bean hulls (SH), wheat bran (WB) and a by-product of wheat flour (F) produced the highest activities of endo-1,4-β-xylanase (Xyl) and endo-1,4-β-D-glucanase (EG) being at least 3 times lower than those obtained by SSF. The highest ratio of Xyl to EG was obtained in SmF with F. Xyl obtained by SmF with WB was the most thermally resistant. The enzymatic extract obtained in SmF using SH presented a high power of saccharification. The production of enzymes for further application such as bioethanol generation process revalue these LW and can help offset growing environmental problems.     

Fermentation optimization for a probiotic local northeastern Indian rice beer and application to local cassava and plantain beer production

Response surface methodology was employed to determine the optimal conditions of time and temperature for the fermentation of a local North East Indian rice beer. The same conditions were then applied to prepare local beers from cassava (Manihot esculanta) and plantain (Musa ABB). Saccharomyces cerevisiae, Aspergillus oryzae and Lactobacillus plantarum were used to carry out the fermentation process. Thirteen experimental runs, based on a two‐factor five‐level design were carried out according to a central composite rotatable design. The independent variables were fermentation time (24–216 h) and temperature (25–40°C). The responses studied were content of protein, alcohol, total polyphenols, reducing sugars as well as titratable acidity and L. plantarum count. Numerical optimization predicted that a fermentation period of 143 h at a temperature of 33°C would result in a desirable rice beer, with response values of protein content OF 0.77%, alcohol content OF 6.99%, L. plantarum count of 7.08 log CFU mL^?1, polyphenol content of 34.46 mg/100 g, reducing sugars of 2.39% and a titratable acidity of 0.34%. Cassava and plantain beers were prepared using the optimized parameters of the rice beer experiments and the resultant beers exhibited the desired chemical parameters, suggesting applicability of the conditions to preparing these types of local beers from a wider range of substrates. Copyright © 2015 The Institute of Brewing & Distilling     

Evaluation of microbial toxins,trace elements and sensory properties of a high-theabrownins instant Pu-erh tea produced using Aspergillus tubingensis via submerged fermentation

Theabrownins (TB) are polymeric phenolic compounds associated with the multiple bioactivities of Pu-erh tea, a post-fermented Chinese dark tea. High-TB instant Pu-erh tea was produced via a novel submerged fermentation (SF) using Aspergillus tubingensis and compared with samples produced commercially via the conventional solid-state fermentation (SSF). Viable microorganisms and microbial toxins, especially aflatoxins B₁, G₁, B₂, G₂, cyclopiazonic acid, fumonisins B₁, B₂, B₃ and ochratoxin A, were below the detection limit in all samples. Fewer microbial metabolites were found in SF instant tea compared with the SSF teas. Based on an adult consuming 1 g of instant Pu-erh tea daily, the dietary intake of investigated elements was below the safe limits recommended by various authorities. Tasters viewed the instant tea infusions as very mild, smooth, mellow and full. This suggested that submerged fermentation using A. tubingensis offers a speedy and safe alternative to commercial production of instant Pu-erh tea.     

Strain Improvement Through UV and Chemical Mutagenesis for Enhanced Citric Acid Production in Molasses-Based Solid State Fermentation

Aspergillus niger was subjected to UV radiation and chemical mutagenesis to develop its hyper-producing mutants for enhanced citric acid production. Ethyl methane sulfonate (EMS) and Ethidium bromide (EB) were used for chemical mutagenesis of Aspergillus niger. UV, and chemically treated mutants of Aspergillus niger were identified by using 2-deoxy, D-glucose as selective marker. The selected mutants were cultured in solid state fermentation (SSF) of sugarcane molasses medium (10%) using corn cobs, banana stalk, sugarcane bagasse, wheat straw, and wheat bran as carrier substrates. After pH adjustment and sterilization, the triplicate flasks were inoculated with 5 mLof homogenous spore suspensions of selected mutants of A. niger and the flasks were subjected to SSF under still culture conditions. The mutant EB-3 (treated with 1 mg/mL ethidium bromide for 120 min) giving highest citric acid yield (64.2 mg/mL) in 72 h was selected as hyper-producing mutant. Citric acid production process using EB-3 mutant was then optimized to enhance citric acid production by the mutant in SSF. Aspergillus niger EB-3 mutant could produce 67.72 mg/mL citric acid in 72 h using banana stalks as support material under optimum conditions of pH (pH 6), incubation temperature (35°C) and inoculum size (5 mL) in SSF.     

Effect of fermentation conditions on the antioxidant compounds and antioxidant capacity of <Emphasis Type="Italic">Lupinus angustifolius cv. zapaton</Emphasis>

To study the effect of fermentation on the antioxidant compounds and antioxidant capacity of Lupinus angustifolious cv. zapaton, two different types of fermentation processes were performed. Solid-state fermentations in cracked seeds carried out by Aspergillus oryzae, Rhizopus oryzae and Bacillus subtilis and liquid state fermentations in flour and cracked seeds carried out by the microbial population present in the seed (natural fermentation) or by L. plantarum inocula. Antioxidant compounds that were quantified included vitamin C by micellar electrokinetic capillary electrophoresis, vitamin E isomers by high performance liquid chromatography, total phenolic compounds (TPC) by spectrophotometry and reduced glutathione (GSH) by spectrofluorimetry. The antioxidant capacity was analysed by determining the superoxide dismutase-like activity (SOD-like activity), Peroxyl Radical-Trapping Capacity (PRTC) and Trolox Equivalent Antioxidant Capacity (TEAC) and by in vitro methods using unilamellar liposomes of egg yolk phosphatidylcholine (PC). In general, fermentation process produced a reduction in vitamin C, vitamin E activity, GSH and SOD-like activity, however TPC, PRTC, TEAC and inhibition of PC peroxidation increased under most of the fermentation conditions. Optimal results to obtain functional lupin products were achieved in cracked seeds fermented with B. subtilis where increases in TPC content, PRTC, inhibition of PC peroxidation and TEAC content of 490, 669, 492 and 224%, respectively, were found. Also, fermentation carried out with L. plantarum in lupin flours and naturally in cracked seeds caused smaller, although significant (P ≤ 0.05) increases in TPC, PRTC, inhibition of PC and TEAC (80–148, 50–90, 23 and 45–65%, respectively).     

Effect of bioaugmentation on biochemical characterisation and microbial communities in Daqu using Bacillus,Saccharomycopsis and Absidia

Daqu, a saccharifying and fermenting agent for the production of Chinese vinegar and liquor, is manufactured through a spontaneous solid-state fermentation process (SSF). To investigate the influence of bioaugmentation with native microorganisms on Daqu SSF process, physicochemical properties, microbial biomass, volatile compounds and microbial communities were analysed in laboratory-scale Daqu. The results showed that the amylase activity of Daqu enhanced 6.35% ± 0.74% by inoculating Bacillus amyloliquefaciens, Saccharomycopsis fibuligera and Absidia corymbifera. Obviously higher microbial richness was found in the Daqu with bioaugmentation, although the microbial community structure remained relatively stable. Moreover, a total of twenty-two volatile compounds were detected in the mature Daqu. Slightly increase in the content of alcohols was found in the enhanced group by fungal inoculation, including ethanol (46.58 ± 1.36 mg kg⁻¹), isobutanol (0.19 ± 0.04 mg kg⁻¹) and isoamyl alcohol (1.55 ± 0.13 mg kg⁻¹). This study demonstrated that bioaugmentation had a positive effect on the amylase activity, main volatile compounds and microbial community richness.     

Juice extraction from mango pulp using an enzymatic complex of Trichoderma sp. produced by solid-state fermentation

In this study, 2 Trichoderma strains (T-I and T-II) were evaluated for the production, by submerged (SmF) and solid state fermentation (SSF) of an enzymatic complex with the capacity to degrade the cell components of mango peels, using these as support (in SSF) and source of nutrients. Highest enzymatic activity (7,552.5 units of endo-glucanase/L) was found in T-II by SSF. Efficiency of this crude enzymatic extract in the extraction of mango juice was evaluated, improving the yield up to 79%, representing an alternative to give an added value of mango peels improving the yields of production of mango juice.     

Influence of the addition of lupin sourdough with different lactobacilli on dough properties and bread quality

The aim of this research was to study the effects of solid‐state fermentation (SSF) with Lactobacillus sakei, Pediococcus pentosaceus and P. acidilactici on lupine sourdough parameters and lupine sourdough influence on the physical dough properties and wheat bread quality. The results showed that lactic acid bacteria (LAB) significantly reduced the pH and increased total titratable acidity (TTA) of SSF lupine. The highest protease activity in lupine is excreted by L. sakei (187.1 ± 8.6 PU g^?1), and the highest amylase activity, by P. pentosaceus (155.8 ± 7.5 AU g^?1). Lupine sourdough has a significant effect on the rheological properties of doughs, which affect the baking characteristics of the final product. In conclusion, it can be said that L. sakei, P. pentosaceus and P. acidilactici could be used for lupine SSF, and the addition of up to the 10% SSF lupine products increases the wheat–lupine bread quality.     

Improving Bioethanol Yield: The Use of Solid‐State Fermentation Products Grown on DDGS

In a climate of uncertain prices for grain and fuel, conservation and efficiency are more important than ever. Many agro‐industrial residues are excellent substrates for solid‐state fermentation (SSF). Dried distillers grains with solubles (DDGS) are an important co‐product of the ethanol industry and have potential as a substrate for solid‐state fermentation. SSF products were produced using DDGS from a distillery and DDGS from a fuel ethanol plant as the fungal growth substrate. The spent grains were inoculated with GRAS (Generally Regarded As Safe) organisms Aspergillus orzyae and Rhizopus oligosporus. After growth, the resultant SSF product was dried and used as an enzyme complex supplement that was added to laboratory scale standard fuel ethanol corn mash fermentations. Improved ethanol yields were consistently observed. The use of solid‐state fermentation to produce unique enzyme complexes on DDGS offers a novel way to increase the value of the DDGS and to enhance bioethanol fermentation.     

Bioprocessing of pineapple waste for sustainable production of bioactive compounds using solid-state fermentation

The bioprocessing of pineapple wastes into value-added bioproducts is a sustainable solution. This study examined a novel alternative for producing bioactive compounds using Aspergillus niger GH1 for solid-state fermentation (SSF) of pineapple peel and core. The results revealed that the chemical composition of pineapple waste was suitable for use in SSF. During the first 32 h of the SSF, free phenols increased by 72.31% and were positively related to antioxidant activity as measured by DPPH (2,2-diphenyl-1-picrylhydrazyl). ß-Glucosidase and cellulase activities were increased by the SSF and were positively associated with free phenolic acids such as 5-caffeoylquinic acid. Scanning electron microscopy (SEM) confirmed mycelial invasion in pineapple waste. Analysis of free and bound phenols by high-performance liquid chromatography-mass spectrometry (HPLC-MS) showed more conjugated phenols in the unfermented than fermented waste. These results provided a broad overview of the chemical compounds with antioxidant capacity that are generated from the growth of A. niger.Industrial relevanceThe market for polyphenols and enzymes is expected to grow exponentially in the coming years. In response to this requirement and to the circular economy that seeks to take advantage of waste by generating new products, solid-state fermentation is applied, which produces in a short time polyphenols with antioxidant capacity and enzymes with possible application in the food industry from the fermentation of organic waste such as pineapple waste.     

Comparison of releasing bound phenolic acids from wheat bran by fermentation of three Aspergillus species

Wheat bran was fermented at 28 °C for 7 days under 70% humidity by Aspergillus niger, Aspergillus oryzae and Aspergillus awamori. Total phenolic content (TPC) of the unfermented sample was 1531.5 μg g^?1 wheat bran. After the fermentation of Aspergillus awamori, Aspergillus oryzae and Aspergillus niger, TPC reached 5362.1, 7462.6 and 10 707.5 μg g^?1, respectively. The antioxidant activity in the extractions of fermented wheat bran also increased significantly compared with the unfermented sample (P < 0.05). Aspergillus niger showed the greatest capacity to release bound ferulic acid (416.6 μg g^?1). Aspergillus oryzae and Aspergillus awamori had the advantages of releasing more chlorogenic acid (84.0 μg g^?1) and syringic acid (142.3 μg g^?1), respectively. The destructive effect of Aspergillus niger on wheat bran structure was the strongest, followed by that of Aspergillus oryzae. This effect of Aspergillus niger may be due to its higher cellulase, xylanase, arabinofuranosidase and β‐xylosidase activities. Besides, Aspergillus oryzae possessed higher β‐glucosidase activity, and Aspergillus awamori had higher α‐amylase and feruloyl esterase activities. Aspergillus niger may be the best to release bound phenolic acids in the three Aspergillus species. These will provide the helpful information for understanding mechanism of the fermentation by Aspergillus species releasing bound phenolic in wheat bran.     

Application of whey of Mozzarella di Bufala Campana fermented by lactic acid bacteria as a bread biopreservative agent

A total of nine isolated lactic acid bacteria (LAB) from tomato and sourdough with antifungal activity were employed to revaluate the whey of Mozzarella di Bufala through the fermentation process for 72 h at 37 °C. Then, the fermented whey (BWF) was characterised and used as biopreservative in bread formulation. L. plantarum TR7 and L. plantarum TR2 strains showed average lactic acid concentration in BWF of 13.8 g L⁻¹. Also, the bread volatile organic compounds (VOC) analysis showed an increase in hexanal, benzeneacetaldehyde, benzaldehyde and pyrazine tetramethyl when using BWF as ingredient. Moreover, the DPPH-inhibitory activity of bread with BWF extract also reflected a 33% rise in comparison with control bread. The application of BWF as a biopreservation agent in bread showed an increase in shelf life compared with bread with 0.3% calcium propionate and bread control for 2 and 15 days, respectively. BWF can be used as an interesting biopreservation strategy of bread.     

3种固态发酵生物量测定方法的比较

对固态发酵中生物量测定常用的3种细胞组分（核酸、麦角固醇、氨基葡萄糖）作为生物量测定指标的可行性进行了比较研究。结果表明：核酸组分在细胞中含量比较稳定，可较好地指示生物量的变化，氨基葡萄糖受培养基成分影响较大，只适舍固定成分培养基中生物量的表征，而麦角固醇在细胞中的含量不太稳定，不适合作为生物量测定的指标。运用核酸法对土曲霉田态发酵产lovastatin过程中的菌体量变化进行了描述。     

Increasing peptide yield of soybean meal solid-state fermentation of ultrasound-treated Bacillus amyloliquefaciens

The purpose of the study was to investigate the feasibility and mechanisms of increasing peptide yield of soybean meal solid-state fermentation (SSF) products by ultrasound-treated Bacillus amyloliquefaciens. Under the optimal parameters level (frequency of 40 kHz, power density of 40 W/L, time of 17.5 min), peptide content of SSF soybean meal in ultrasonic treatment group reached 150.68 mg/g, which increased by 13.10% compared to the control. Ultrasound-treated B. amyloliquefaciens enhanced peptide yield, biomass and protease activity at early stage of SSF. Analysis of omics and qRT-PCR validated that ultrasound treatment did not promote protease secretion but facilitated the germination of endospores. The germination rate increased from 15.67% to 67.33%. According to growth curve determination, ultrasound-treated B. amyloliquefaciens had shorter lag times due to increased vegetative cell content in the inoculum. In conclusion, peptide yield of soybean meal SSF products can be effectively increased by ultrasound-treated B. amyloliquefaciens, which is because of the facilitation effect of ultrasound on endospores germination.