Solid-state Fermentation Cultures Research Articles

Comparative analysis of metabolites and in vitro hypoglycemic activity of Taiwanofungus camphoratus cultured using various methods

Taiwanofungus camphoratus has attracted much attention because it can abundantly produce various active substances that exhibit blood-sugar lowering, immunity improving, and antioxidant properties. Currently, T. camphoratus is cultured using four main methods: cutting wood culture, solid-state fermentation, submerged fermentation, and dish culture. T. camphoratus produces different metabolites under different culture methods. In this study, nontargeted metabolomics was used to compare the metabolites of T. camphoratus produced under these four culture methods. Principal component analysis and supervised partial least squares-discriminant analysis were used to analyze the differences in the metabolites. Moreover, in vitro hypoglycemic activity of T. camphoratus extracts produced under four culture methods was compared by assessing their ability to inhibit the activity of α-glucosidase, α-amylase, and sucrase. A total of 186 metabolites were identified. In total, 127 metabolites were common under the four culture methods. Under solid-state fermentation, submerged fermentation, and cutting wood culture, 12, 1, and 4 metabolites were unique, respectively. The differential metabolites produced by T. camphoratus under four culture methods were mainly triterpenoids, phenolic compounds, and fatty acid compounds. α-glucosidase, α-amylase, and sucrase activity inhibition was the best using T. camphoratus extract obtained under cutting wood culture; the inhibition rates were 55.97%, 51.96%, and 78.02%, respectively, which were comparable to those exhibited by 0.001, 3, and 12 mg/mL acarbose (positive control). The metabolites produced by T. camphoratus and α-glucosidase, α-amylase, and sucrase inhibitory activities were different under the four culture methods. Cutting wood culture exhibited the best enzyme inhibitory activity. This study provided a theoretical basis for further use and development of various culture methods for the rational production of active metabolites of T. camphoratus.

Storage stability of fluid bed dried solid state fermented (SSF) lactic cultures inmilk

The present investigation was intended to study theeffect of storage at ambient temperature on the fluid beddried powder of Solid State Fermented (SSF) lactic cultures such as dahi, yoghurt and probiotic cultures and also made an attempt to check the performance in milk. The SSF cultures were prepared from various dhals and screened for the survival of bacterial aerobic spore, the raw black gram dhal showed lowest spore count of 1.52 log10cfu/g. Combination of hot air oven exposure of black gram dhal at 1000C/1 h and sterilization at 1210C/30 min completely destroyed the spores. On fermentation the maximum viable counts of dahi (8.41log10cfu/g), yoghurt (8.98log10cfu/g) andprobiotic (9.47log10cfu/g) cultures were obtainedon black gram dhal containing 1:0.8 ratio of moisture was supplemented with 1% level of skim milk powder, ash gourd, carrot and tomato juices as they provided growth promoting agents. The fermented SSF cultures were subjected for fluid bed drying for 1.5 h at ambient temperature (250C).The SSF culture viability upon fluid drying decreased from 8.65 to 8.33, 9.01 to 8.85 and 9.65 to 9.34log10cfu/g in case of dahi, yoghurt and probiotic cultures, with the moisture content of 9.4%. When these dried powders of SSF cultures of dahi, yoghurt and probiotic cultures were inoculated at 1,0.5 and 3% to heated milk, the cultures took 5:00, 3:30 h and 9:30 h to set the heat treated milk with acidity of 0.68, 0.71 and 0.59% lactic acid respectively. The dried SSF lactic cultures possessed viability of 6 log10cfu/g till 24th days of storage at ambient temperature (28±10C) and these cultures showed absence for the contaminants like coliforms, aerobic spores and yeast and molds. With respect to performance, the curdling time increased with theincreased storage days at ambient temperatures due to the reduction in viable lactic counts.

The effect of fermentation by Bacillus subtilis and Aspergillus niger on the nutritional value of date palm kernels

This study was performed to investigate the effect of fermentation by Bacillus subtilis (B. subtilis) and Aspergillus niger (A. niger) and alkaline processing on the nutritional value and chemical composition of date palm kernels (DPK). DPK was fermented for 28 days under solid-state fermentation culture with two different microorganisms (B. subtilis and, or A. niger). Alkaline processing was performed by soaking DPK in NaOH solution for 24 hours. In this experiment, eight treatments were used: DPK (control), DPK fermented by B. subtilis, and A. niger separately or in combination, and processed with NaOH, alone or with B. subtilis or A. niger or both. Digestibility and gas production of fermented and processed DPK were performed using the batch culture and gas production techniques. The results showed that there was an increase in crude protein (CP) and a decrease in crude fiber concentrations due to the fermentation of DPK with B. subtilis and A. niger (P < 0.05). Total phenol content in fermented DPK (FDPK) with B. subtilis and A. niger was significantly lower than the control. Gas production significantly increased in FDPK compared to control and NaOH-treated samples (p <0.05). All treatments significantly increased the in vitro digestibility of DM (IVDOD) and OM (IVOMD) compared to the control (p < 0.01). Among the treatments, simultaneous fermentation of DPK with B. subtilis and A. niger had the most significant effect on increasing the microbial CP (MCP) and its efficiency (EMCP; p <0.01).

Process parameters optimization for amylase production through rice bran bioconversion by Aspergillus niger

Enzymes are produced by a wide range of living things including bacteria, fungi, plants and animals. Fungal enzymes are preferred over other microbial sources owing to their widely accepted Generally Regarded As Safe (GRAS) status. Amylase is one of the most widely used enzymes in the biotechnology industry with a global market of over $4 bn as at 2015. However, the synthetic media used for the production of this enzyme is becoming costlier and has become a subject of concern for many food-processing industries. Hence, manufacturers are now in search for alternative approaches to cut down the cost of production. In addition, the Raw Materials Research and Development Council, Nigeria (rmrdc.gov.ng) indicated that the country spends about $200 bn annually on importation of industrial enzymes. Therefore, this study was designed with the aim of utilizing agro-industrial waste (rice bran) as the sole carbon source for the production of amylase in a Solid-State Fermentation (SSF) culture by optimizing the major process parameters. A 19-run experiment generated by Design Expert™ software was carried out to identify the optima for pH, temperature and substrate concentration that would yield the highest amount of amylase. The results of the current study showed that significant interaction effect exists between temperature and pH. However, no interaction was observed with substrate concentration and pH depicting the sensitivity of the enzyme to varying pH conditions. Similarly, a statistically significant 2FI model (p < 0.0022) that could be used to predict the yield of amylase was identified. Conclusively, the findings of this study suggests that the feasibility of using rice bran as an alternative carbon source in the production of amylase calls for its wider utilization in the food processing industries, thus, alleviating the cost concern.

Submerged culture of Penicillium sclerotiorum for production of rotiorin alkaloids by using biosynthetic and chemical catalytic cascade reactions

Red Monascus pigments, azaphilone alkaloids from Monascus sp., have been utilized as natural food colorant more than 1000 years in China. Other azaphilones are being developed as alternative sources of natural pigments. Rotiorin or rotiorin alkaloids are always only achieved by solid-state fermentation or liquid culture without stirring due to carbon/nitrogen metabolism affecting pH of the culture medium and the pH environment further affecting the rotiorin stability/reactivity. In the present work, based on the biocompatible reaction of rotiorin with primary amines using phosphate as catalyst, biosynthesis of rotiorin and chemical conversion of rotiorin into its alkaloids were designed as cascade reactions where rotiorin was prevented from degradation and rotiorin alkaloids were accumulated directly by submerged culture of P. sclerotiorum. This is a facile strategy for direct production of rotiorin alkaloids, which provides the precondition for exploiting rotiorin alkaloids as an alternative source of natural colorant.

Role of microbial lipases in transesterification process for biodiesel production

Bio-diesel is a fuel produced by transesterification reaction of oil or fat in the presence of a catalyst. It is an alternate renewable source for petrol and diesel, which helps in reducing greenhouse gases emissions. Chemical catalysts such as sodium hydroxide, potassium hydroxide, sulfuric acid are used in the conventional methods of biodiesel production. This review focusses on application of lipase enzyme in transesterification of different types of oils such as: soybean, sunflower, rapeseed, palm oil, and waste cooking oil. Worldwide production of biodiesel via lipase enzyme and its economic as well as future aspects are also discussed. Various researchers have used free lipase in biodiesel production however, some lipases are also utilized as immobilized form. There are number of fungal and bacterial species that have been used to synthesize lipases, some of the microbial species are as follows: Aspergillus niger, Burkholderia cepacia, Pseudomonas aeruginosa, Staphylococcus epidermidis etc. Solid-state fermentation and broth culture of fungus is suitable for crude lipase production. Immobilized lipase plays very significant role in transesterification process. Lipases enzymes act as a good catalyst therefore, its production and utilization may be a better alternative of chemical catalysts.

Chaetomadrasins A and B, Two New Cytotoxic Cytochalasans from Desert Soil-Derived Fungus Chaetomium madrasense 375.

Two new cytochalasans, Chaetomadrasins A (1) and B (2), along with six known analogues (3–8), were isolated from the solid-state fermented culture of desert soil-derived Chaetomium madrasense 375. Their structures were clarified by comprehensive spectroscopic analyses, and the absolute configurations of Compounds 1 and 2 were confirmed by electronic circular dichroism (ECD) and calculated ECD. For the first time, Chaetomadrasins A (1), which belongs to the chaetoglobosin family, is characterized by the presence of all oxygen atoms in the form of Carbonyl. Chaetomadrasin B (2) represents the first example of chaetoglobosin type cytochalasan characterized by a hydroxy unit and carbonyl group fused to the indole ring. Compounds 1 and 2 displayed moderate cytotoxicity against HepG2 human hepatocellular carcinoma cells.

Secondary Metabolites from the Fungus Chaetomium elatum CIB-412

One new compound, chaetoglobinol B (1), along with six known secondary metabolites 2–7, was isolated and identified from the solid-state fermented rice culture of the fungus Chaetomium elatum cib-412. In addition, compounds 1–3 showed strong inhibitory activity against α-glycosidase at the concentration of 2.5 mg/mL.

Evaluation of laccase production by Ganoderma lucidum in submerged and solid-state fermentation using different inducers.

Laccases are multicopper oxidases with high potential for industrial applications. Several basidiomycete fungi are natural producers of this enzyme; however, the optimization of production and selection of inducers for increased productivity coupled with low costs is necessary. Lignocellulosic residues are important lignin sources and potential inducers for laccase production. Pinus taeda, a dominant source of wood-based products, has not been investigated for this purpose yet. The aim of this study was to evaluate the production of laccase by the basidiomycete fungus Ganoderma lucidum in the presence of different inducers in submerged and solid-state fermentation. The results of submerged fermentation in presence of 5 μM CuSO 4 , 2 mM ferulic acid, 0.1 g/L P. taeda sawdust, or 0.05 g/L Kraft lignin indicated that although all the tested inducers promoted increase in laccase activity in specific periods of time, the presence of 2 mM ferulic acid resulted in the highest value of laccase activity (49 U/L). Considering the submerged fermentation, experimental design following the Plackett-Burman method showed that the concentrations of ferulic acid and P. taeda sawdust had a significant influence on the laccase activity. The highest value of 785 U/L of laccase activity on submerged fermentation was obtained on the seventh day of cultivation. Finally, solid-state fermentation cultures in P. taeda using ferulic acid or CuSO 4 as inducers resulted in enzymatic activities of 144.62 and 149.89 U/g, respectively, confirming the potential of this approach for laccase production by G. lucidum.

Enrichment of cordycepin for cosmeceutical applications: culture systems and strategies.

Cordyceps spp. is the herbal medication initially used in China and has been reported as the unique resource of cordycepin. Cordycepin exhibits many health benefits, including anti-photoaging and anti-pigmentation; therefore, it potentially is a bioactive ingredient of cosmetic products. In order to enrich cordycepin content in Cordyceps, two artificial cultivation procedures, which are solid-state fermentation and liquid culture, were developed and optimized. The aim of this review is to illustrate cordycepin biosynthesis pathway in Cordyceps, and its bioactivity for cosmeceutical applications, as well as comparing the two different cultivation procedures. The basic model of artificial cultivation of Cordyceps is introduced; meanwhile, the potential application of modern biotechnology to the artificial cultivation is also discussed. This review should be of interest to the readers for the development of cordycepin bioproduction in order to be applied in cosmeceutical industry and some other uses.

Recovery of glucose from dried distiller's grain with solubles, using combinations of solid-state fermentation and insect culture.

A bioethanol by-product, dried distiller's grains with solubles (DDGS) contains high levels of cellulose and starch. We hypothesized that combinations of solid-state fermentation (SSF) and digestion by black soldier fly larvae (BSFL) (Hermetia illucens) could increase the recovery of glucose from this by-product by concentrating and loosening the cellulose matrix through their activities. DDGS was individually fermented with Aspergillus niger, Aspergillus fumigatus, Trichoderma koningii, Phanerochaete chrysosporium, or Lactobacillus plantarum. The fermented DDGS was fed to BSFL, and glucose recoveries from spent feeds were conducted. SSF increases lipid and protein contents, supporting BSFL growth, and weakens the cellulosic matrix. BSFL use nutrients in SSF-DDGS, further concentrating and weakening the cellulose, i.e., DDGS is halved without changing the cellulose contents. For example, Lactobacillus plantarum SSF with BSFL culture concentrates the cellulose content from 9.7% to 26.5% of spent feed. Glucose recovery was determined using three sequential processes (free glucose determination, weak-acid hydrolysis of amorphous cellulose, and enzymatic hydrolysis of micronized crystalline cellulose). Total glucose obtained from 100 g of DDGS increased from 4.8 to 10.7 g. These results show that the combinations of SSF and BSFL could provide additional fermentable sugars (and insect biomass) from bioethanol by-products, suggesting a high productivity from the same feedstock.

Utilization of Lignocellulose-based Orange Peel Waste for Induced Sporulation of Trichoderma asperellum via Box-Behnken Matrix Design

The feasibility of using orange peel residues as a substrate for induced sporulation of Trichoderma asperellum was evaluated. The Box-Behnken matrix (BBM) design was used to screen the effects of several parameters, including the effect of pH, inoculum, and moisture under solid-state fermentation culture conditions. The study was performed in two experimental steps (screening and optimization). Moisture content and pH were determined to be the most influential parameters on spore production during the screening stage. A Box-Behnken design was used to optimize and to define the interaction of the selected parameters. The moisture content was determined as the most significant parameter affecting spore production. An inoculum of 1 × 106 spores g-1, pH 6.07, and moisture content of 69.0% was the combination of conditions observed to achieve the maximum production of 2.04 × 109 spores g-1. The experimental value of 2.16 × 109 spores g-1 (from the experimental model) showed a good fit to the regressed model, with a standard error of 5%. Based on this work, a high yield of spores was obtained at 144 h of cultivation time, indicating that it is a feasible approach to use orange peel as a substrate for biomass and spore production.

Terretonin N: A New Meroterpenoid from Nocardiopsis sp.

Terretonin N (1), a new highly oxygenated and unique tetracyclic 6-hydroxymeroterpenoid, was isolated together with seven known compounds from the ethyl acetate extract of a solid-state fermented culture of Nocardiopsis sp. Their structures were elucidated by spectroscopic analysis. The structure and absolute configuration of 1 were unambiguously determined by X-ray crystallography. The isolation and taxonomic characterization of Nocardiopsis sp. is reported. The antimicrobial activity and cytotoxicity of the strain extract and compound 1 were studied using different microorganisms and a cervix carcinoma cell line, respectively.

Immunomodulatory Properties of Filamentous Fungi Cultivated through Solid-State Fermentation on Rapeseed Meal.

Water extracts from solid-state fermentation (SSF) on rapeseed meal using filamentous fungi exhibit interesting immunomodulatory activities in vitro. Immunomodulation was determined by the capacity of the compounds to activate blood neutrophils and to influence cytokine production in human peripheral blood mononuclear cells (PBMC) and mouse bone marrow-derived macrophages (BMDM). Among the strains tested, Aspergillus sojae mycelium and SSF extracts were the most promising in terms of enhancing the immune response. The filamentous fungus was also successfully cultivated in a pre-pilot bioreactor with forced aeration. The results indicated that the extracts not only activated blood neutrophils but also significantly modulated IL-1β cytokine levels with lipopolysaccharide (LPS)-stimulated PBMC and BMDM without any cytotoxicity in immune cells. IL-1β was down-regulated in a dose-dependent manner in the presence of A. sojae crude mycelium and SSF extract with PBMC, which indicated that there was an anti-inflammatory activity, whereas IL-1β secretion was up-regulated in the presence of stimulated BMDM with the highest concentration that was tested (100μg/mL). The non-fermented rapeseed had no effect at the same concentration. SSF culture, as a natural product, may be a good source for the development of functional feed with an immunostimulating effect or could potentially be used in medicinal applications.

Survivability and storage stability of Trichoderma atroviride TRS40 preserved by fluidised bed drying on various agriculture by-products

ABSTRACTAgriculture by-products were applied to proliferate biomass of Trichoderma atroviride TRS40 in solid state fermentation (SSF) cultures. The culture media overgrown with mycelium together with conidia were preserved by fluidised bed drying at various temperatures (50°C, 60°C and 70°C) and the received biopreparations were stored for 12 months. In order to determine the suitability of TRS40 in the production of biopreparations, the influence of preservation process and storage time on their survivability was examined. The three-component mixture proved more effective in the SSF cultures, ensuring TRS40 count at 6.07 × 109 CFU/g dm, which was ca. 6 times higher than in the mono-component medium. TRS40 survivability after preservation at various temperatures ranged from 40.4% to 100%, regardless of carrier type. In turn, after 12-month storage of the biopreparations produced on the three-component medium, regardless of drying temperature, the number of viable cells ranged from 2.43 × 108 to 2.49 × 108 CFU/g dm. Furthermore, selected parameters of growth kinetics in the Bioscreen C system were determined. The storage time of biopreparations had various effects on growth kinetic parameters. In addition, the preserved preparations based on the TRS40 retained their capability for biosynthesis of hydrolases, even after 12 months of storage.

Secretomic Insight into Glucose Metabolism of Aspergillus brasiliensis in Solid-State Fermentation.

The genus Aspergillus is ubiquitous in nature and includes various species extensively exploited industrially due to their ability to produce and secrete a variety of enzymes and metabolites. Most processes are performed in submerged fermentation (SmF); however, solid-state fermentation (SSF) offers several advantages, including lower catabolite repression and substrate inhibition and higher productivity and stability of the enzymes produced. This study aimed to explain the improved metabolic behavior of A. brasiliensis ATCC9642 in SSF at high glucose concentrations through a proteomic approach. Online respirometric analysis provided reproducible samples for secretomic studies when the maximum CO2 production rate occurred, ensuring consistent physiological states. Extracellular extracts from SSF cultures were treated by SDS-PAGE, digested with trypsin, and analyzed by LC-MS/MS. Of 531 sequences identified, 207 proteins were analyzed. Twenty-five were identified as the most abundant unregulated proteins; 87 were found to be up-regulated and 95 were down-regulated with increasing glucose concentration. Of the regulated proteins, 120 were enzymes, most involved in the metabolism of carbohydrates (51), amino acids (23), and nucleotides (9). This study shows the high protein secretory activity of A. brasiliensis under SSF conditions. High glucose concentration favors catabolic activities, while some stress-related proteins and those involved in proteolysis are down-regulated.

Effects of Bacillus amyloliquefaciens ZM9 on bacterial wilt and rhizosphere microbial communities of tobacco

Ralstonia solanacearum, is a known soil-borne pathogen and causative agent of tobacco (Nicotiana tabacum) bacterial wilt (TBW) worldwide. In this study, we evaluated the effect of different biocontrol agent inoculants on TBW and rhizosphere microbial communities. Bacillus amyloliquefaciens strain ZM9 was selected for its antagonistic characteristics against this pathogen in vitro and its ability to colonize crops in pot-based experiments. ZM9 was effective in the control of TBW, and its effects on the tobacco rhizosphere microbial community were accessed using liquid-state fermentation cultures (LSFC) and solid-state fermentation cultures (SSFC) methods. The biocontrol efficacy of LSFC and SSFC groups was increased by 23.51% and 38.20%, respectively compared to the control group. Sequencing of 16S rRNA gene amplicons from the tobacco rhizosphere revealed the tobacco rhizosphere communities were dominated by Proteobacteria, Acidobacteria, Bacteroidetes, Gemmatimonadetes and Actinobacteria, and the relative abundance of R. solanacearum decreased in the biocontrol groups relative to the control group, and was negatively correlated with the abundance of ZM9. The dominant OTUs affiliated with Sphingosinicella, Gemmatimonas and Gp1 with a negative correlation to the abundance of Ralstonia, were the beneficial bacteria for TBW control. In addition, the relative abundance of plant growth promoting rhizobacteria increased in both biocontrol groups. These results suggest an antagonistic effect of ZM9 on bacterial wilt pathogen, thereby highlighting the application of this strain and other potential biocontrol agents for controlling TBW in the field.

Investigating Lignocellulose in Cornstalk Pretreated with Trametes pubescens Cui 7571 to Improve Enzymatic Saccharification

This study investigated the degradation and enzymatic saccharification of cornstalk by white-rot and brown rot fungi. The fungal strains Trametes pubescens Cui 7571, Trametes velutina Dai 10149, and Antrodia wangii Cui 7568 were analyzed in solid-state fermentation cultures. Various extracellular enzyme activities were assessed to determine biochemical changes during the degradation process. Fourier-transform infrared (FTIR) spectroscopy and X-ray diffraction (XRD) analysis were used to determine the structural changes. A correlation analysis between the chemical composition of cornstalk, extracellular enzyme activities, and structural changes indicated that T. pubescens Cui 7571 broke down lignin efficiently and subsequently degraded cellulose, and hemicellulose digestion was not affected by the lignin barrier. Enzymatic hydrolysis demonstrated that the T. pubescens Cui 7571-pretreated samples increased cellulose and hemicellulose conversion in cornstalk. Overall, T. pubescens Cui 7571 displayed excellent performance as a biological pretreatment agent, and lignin played a significant role in the enzymatic saccharification of cornstalk.

A New Orsellinic Acid Derivative from the Fungus Chaetomium megalocarpum

A new orsellinic acid derivative, orsellide A1, together with orsellide A, orsellide D, and orsellinic acid, was isolated from the ethyl acetate extract of the solid-state fermented rice culture of the Chaetomium megalocarpum cib-135 fungus. The structure of orsellide A1 (1) was confirmed to be 2-O-(2,4-dihydroxy-6-methylbenzoyl)-6-deoxy-1-O-ethyl-3-keto-α-D-ribo-hexopyranoside on the basis of spectroscopic analysis.

Penicillium janthinellum: a source of efficient and high levels of β-glucosidase.

Penicillium janthinellum strain isolated from leaf litters of oak trees from montane alpine forests of Shivalik hills (India) produced high levels of β-glucosidase both during solid-state fermentation (796 units/gds) and shake flask cultures (65.3 units/ml). The peptide mass fingerprinting of the secretome showed a variety of glycosyl hydrolases. β-Glucosidase was purified and characterized to be a GH3 family member that had a molecular weight (M r) of 101 kDa and pI of 4.5. β-Glucosidase was optimally active at 60 °C at pH 5.0 but showed appreciable activity and thermostability under alkaline conditions (pH 9.0) also. β-Glucosidase activity was positively modulated in the presence of Mn(2+) ions. The enzyme preferentially catalyzed the hydrolysis of p-nitrophenol-β-D-glucopyranoside (pNPG) but also recognized cellobiose as substrates. K m and V max for the hydrolysis of pNPG by β-glucosidase were calculated as 3.3 mM and 444 μmol min(-1) mg protein(-1). Purified β-glucosidase showed transglycosylation activity in the presence of methanol as an acceptor molecule.