Solid-state Fermentation For Production Research Articles

<b>Analytical modeling and numerical optimization of the biosurfactants production in solid-state fermentation by <i>Aspergillus fumigatus</i></b> - doi: 10.4025/actascitechnol.v36i1.17818

This is an experimental, analytical and numerical study to optimize the biosurfactants production in solid-state fermentation of a medium containing rice straw and minced rice bran inoculated with Aspergillus fumigatus. The goal of this work was to analytically model the biosurfactants production in solid-state fermentation into a column fixed bed bioreactor. The Least-Squares Method was used to adjust the emulsification activity experimental values to a quadratic function semi-empirical model. Control variables were nutritional conditions, the fermentation time and the aeration. The mathematical model is validated against experimental results and then used to predict the maximum emulsification activity for different nutritional conditions and aerations. Based on the semi-empirical model the maximum emulsification activity with no additional hydrocarbon sources was 8.16 UE·g-1 for 112 hours. When diesel oil was used the predicted maximum emulsification activity was 8.10 UE·g-1 for 108 hours.

Solid state fermentation of food waste mixtures for single cell protein, aroma volatiles and fat production

Growth of selected microorganisms of industrial interest (Saccharomyces cerevisiae, Kluyveromyces marxianus and kefir) by solid state fermentation (SSF) of various food industry waste mixtures was studied. The fermented products were analysed for protein, and nutrient minerals content, as well as for aroma volatile compounds by GC/MS. The substrate fermented by K. marxianus contained the highest sum of fat and protein concentration (59.2% w/w dm) and therefore it could be considered for utilisation of its fat content and for livestock feed enrichment. Regarding volatiles, the formation of high amounts of ε-pinene was observed only in the SSF product of kefir at a yield estimated to be 4kg/tn of SSF product. A preliminary design of a biorefinery-type process flow sheet and its economic analysis, indicated potential production of products (enriched livestock feed, fat and ε-pinene) of significant added value.

Statistical studies on high molecular weight pullulan production in solid state fermentation using jack fruit seed

The purpose of the work was to optimize the medium variables for maximizing pullulan production using jack fruit seed as a low cost substrate by Aureobasidium pullulans in solid state fermentation. Effects of K2HPO4, KH2PO4, ZnSO4·5H2O, MgSO4·7H2O, NaCl, (NH4)2SO4·5H2O, yeast extract, moisture content (%, w/w) in the production medium on pullulan production were studied using Plackett–Burman design. Production of pullulan was significantly affected by the medium variables namely KH2PO4, ZnSO4·5H2O, NaCl and moisture content (%, w/w). Then screened variables were optimized by Box Behnken experiment design. The pullulan obtained was characterized and confirmed by FTIR, 1H NMR and 13C NMR. Molecular weight of pullulan was found to be 1.733×106g/mol by gel permeation chromatography (GPC).

Pectinase production by Aspergillus niger isolated from decomposed apple skin

Pectinase activity among twelve different fungal strains, Aspergillus niger IM09 was identified as a potential one to produce maximal level 831 U/g at pH 4.0. Media composition, incubation temperature, incubation time, substrate concentration, aeration, inoculum size, assay temperature and nitrogen sources were found to effect pectinase activity. Moisture content did not affect the activity significantly. Media composition was varied to optimize the enzyme production in solid state fermentation. It was observed that the highest pectinase activity of 831.0 U/g was found to produce in presence of yeast extract as a nitrogen source in combination with ammonium sulfate in assay media. Aeration showed positive significant effects on pectinase production 755 U/g at 1000 ml flasks. The highest pectinase production was found at 2 g pectin (521 U/g) used as a substrate. Pectinolytic activity was found to have undergone catabolite repression with higher pectin concentration (205 U/g at 5 g pectin). The incubation period to achieve maximum pectinase activity by the isolated strain Aspergillus niger IM09 was 3 days, which is suitable from the commercial point of view. DOI: http://dx.doi.org/10.3329/bjsir.v48i1.15410 Bangladesh J. Sci. Ind. Res. 48(1), 25-32, 2013

Enhanced viability of Lactobacillus reuteri for probiotics production in mixed solid-state fermentation in the presence of Bacillus subtilis

In order to develop a multi-microbe probiotic preparation of Lactobacillus reuteri G8-5 and Bacillus subtilis MA139 in solid-state fermentation, a series of parameters were optimized sequentially in shake flask culture. The effect of supplementation of B. subtilis MA139 as starters on the viability of L. reuteri G8-5 was also explored. The results showed that the optimized process was as follows: water content, 50 %; initial pH of diluted molasses, 6.5; inocula volume, 2 %; flask dry contents, 30∼35 g/250 g without sterilization; and fermentation time, 2 days. The multi-microbial preparations finally provided the maximum concentration of Lactobacillus of about 9.01 ± 0.15 log CFU/g and spores of Bacillus of about 10.30 ± 0.08 log CFU/g. Compared with pure fermentation of L. reuteri G8-5, significantly high viable cells, low value of pH, and reducing sugar in solid substrates were achieved in mixed fermentation in the presence of B. subtilis MA139 (P < 0.05). Meanwhile, the mixed fermentation showed the significantly higher antimicrobial activity against E. coli K88 (P < 0.05). Based on the overall results, the optimized process enhanced the production of multi-microbe probiotics in solid-state fermentation with low cost. Moreover, the viability of L. reuteri G8-5 could be significantly enhanced in the presence of B. subtilis MA139 in solid-state fermentation, which favored the production of probiotics for animal use.

Bioconversion of Oil Palm Frond by Aspergillus niger to Enhances It’s Fermentable Sugar Production

The aim of this study was to develop an economical bioprocess to produce the fermentable sugars at laboratory scales Using Oil Palm Frond (OPF) as substrate in Solid State Fermentation (SSF). OPF waste generated by oil palm plantations is a major problem in terms of waste management. However, this lignocellulosic waste material is a cheap source of cellulose. We used OPF as substrate to produce fermentable sugars. The high content of cellulose in OPF promises the high fermentable sugars production in SSF. Saccharification of OPF waste by A. niger USMAI1 generates fermentable sugars and was evaluated through a solid state fermentation. Physical parameters, e.g., inoculum size, initial substrate moisture, initial pH, incubation temperature and the size of substrate were optimized to obtain the maximum fermentable sugars from oil palm fronds. Up to 77 mg of fermentable sugars per gram substrate was produced under the optimal physical parameter conditions. Lower productivity of fermentable sugars, 32 mg fermentable sugars per gram substrate was obtained under non optimized conditions. The results indicated that about 140.6% increase in fermentable sugar production after optimization of the physical parameters. Glucose was the major end component amongst the fermentable sugars obtained. This study indicated that under optimum physical parameter conditions, the OPF waste can be utilized to produce fermentable sugars which then convert into other products such as alcohol.

Rapid enzyme production and mycelial growth in solid-state fermentation using the non-airflow box

Solid-state fermentation (SSF) has become an attractive alternative to submerged fermentation (SMF) for the production of enzymes, organic acids, and secondary metabolites, while there are many problems during the culture of SSF. We recently created a SSF system using a non-airflow box (NAB) in order to resolve the problems, which enabled the uniform culture in the whole substrate and high yield of many enzymes. In this paper, further characterization of SSF using the NAB was carried out to obtain other advantages. The NAB culture under the fixed environmental condition exhibited a rapid increase in enzyme production at earlier phase during the culture compared with conventional SSF. Total mycelial growth also exhibited the same trend as enzyme production. Thus, the increase in the rate of the enzyme production was thought to mainly be attributed to that of the growth. To support it, it was suggested that the NAB culture resulted in most optimal water activity for the growth just at the log phase. In addition, the NAB culture was able to achieve high reproducibility of enzyme production, derived from uniform condition of the substrate during the culture. The results indicate that the NAB culture has many benefits for SSF.

Purification and characterization of xylanase from Aspergillus fumigatus isolated from soil

The objectives of the present study were to purify and characterize xylanase enzyme from the fungus obtained from soil. A total of 40 fungi were isolated from 25 soil samples collected after primary screening on Potato Dextrose Agar. In the secondary screening (malt extract agar, 0.5% birch wood xylan), based on the diameter of the clear zone, the fungus was identified as Aspergillus fumigatus by microbial type culture collection (MTCC), Chandigarh, India and was selected for xylanase enzyme production in solid state fermentation using wheat bran. Xylanase was subjected to a three-step purification scheme involving ammonium sulphate precipitation, gel filtration chromatography and anion exchange chromatography. Purity was verified by running the extracted protein on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and a single band was observed. When compared with the standard wide range protein molecular markers on SDS-PAGE, it was found to have a molecular weight of 43 KDa. The Km and Vmax value of xylanase was 3.12 mg/ml and 2857 μmol/min/mg protein as obtained from a Lineweaver-Burk plot. The optimal temperature and pH was found to be 30 and 10°C, respectively. After 4 h of incubation, enzyme retained 100% activity at 30°C. Xylanase was incubated at various pH levels (2 to 12) for 4 h at 30°C, and the residual activity was measured. More than 65% of the original activity was retained at pH ranging from 4 to 10 after 4 h.

Comparative characterization of proteins secreted by Neurospora sitophila in solid-state and submerged fermentation

Although submerged fermentation (SmF) accounts for most of current enzyme industries, it has been reported that solid-state fermentation (SSF) can produce higher enzyme yields in laboratory scale. In order to understand the reasons contributing to high enzyme production in SSF, this study compared the cellulase activities and secretomes of Neurospora sitophila cultured in SSF and SmF using steam exploded wheat straw as carbon source and enzyme inducer. The total amounts of protein and biomass (glucosamine content) in SSF were respectively 30 and 2.8 times of those inSmF. The CMCase, FPA and β-glucoside activities in SSF were 53-181 times of those in SmF. Both in SSF and SmF,N.sitophila secreted the most critical cellulases and hemicellulases known for Trichoderma reesei, although a β-xylosidasewas exclusively identified in SSF. Six endoglucanases were identified in N.sitophila secretion with the high CMCase activity. The non-enzyme proteins in SSF were involved in fungal mycelia growth and conidiation; while those in SmF were more related to glycometabolism and stress tolerance. This revealed that SSF more likely serves as a natural habitat for filamentous fungi to facilitate the enzyme secretion.

Stepwise optimisation of enzyme production in solid state fermentation of waste bread pieces

When it is not consumed, bread presents a major source of food waste, both in terms of the amount and its economic value. However, bread also possesses the characteristics of an ideal substrate for solid state fermentation. Yet nearly all wasted bread ends up in landfill sites, where it is converted into methane by anaerobic digestion. Governments are finally taking action and, according to the EU Landfill Directive, for example, biodegradable municipal waste disposed into landfills must be decreased to 35% of 1995 levels, by 2020. Solid state fermentation of waste bread for the production of value added products is a novel idea, which could help with the achievement of this target. In this study, glucoamylase and protease production from waste bread pieces, via solid state fermentation, was investigated in detail. The optimum fermentation conditions for enzyme production were evaluated as, 20mm particle size, 1.8 (w/w, db) initial moisture ratio, and duration of 144h. Under these conditions, glucoamylase and protease activities reached up to 114.0 and 83.2U/g bread (db), respectively. This study confirms that waste bread could be successfully utilised as a primary raw material in cereal based biorefineries.

Intensification of Fructosyltransferases and Fructo-Oligosaccharides Production in Solid State Fermentation by Aspergillus awamori GHRTS

The present work was aimed to investigate the impact of the solid substrates mixture on Fructosyltransferases (FTase) and Fructo-oligosaccharides (FOS) production. An augmented simplex lattice design was used to optimize a three component mixture for FTase production. Among selected substrates corn cobs has highest impact on FTase production followed by wheat bran and rice bran. All two substrates and three substrate combinations showed the highest enzyme production than their individual levels. Among the tested various models quadratic model was found to be the best suitable model to explain mixture design. Corncobs, wheat bran and rice bran in a ratio of approximately 45:29:26 is best suitable for the FTase production by isolated Aspergillus awamori GHRTS. This study signifies mixture design could be effective utilize for selection of best combination of multi substrate for improved production of high value products under solid state fermentation.

Valorization of grape pomace and orange peels: Improved production of hydrolytic enzymes for the clarification of orange juice

The production in solid state fermentation (SSF) of several hydrolytic enzymes by Aspergillus awamori on a mixture of grape pomace and orange peels has been studied in two configurations of bioreactor: packed bed and tray-type. When the effect of aeration in both reactors was compared, using the trays-type with an air flow rate of 3mL/gds·min, average activities of 42.64 and 2.16IU/gds were measured for xylanase and CMCase, respectively; however in the case of the column reactor the aeration must be doubled to obtain similar activity values. These differences were more significant in the case of exo-PG. The extracts obtained in this reactor were applied to orange juice and the cloudiness was markedly reduced, even improving the efficiency of a commercial enzyme preparation. Thus, while the turbidity of the fresh juice was 4625 NTU, treatment with the extracts reduced the value to 24.25 NTU. In a similar way the clarity increased to 95% after treatment with enzyme extracts. According to the results obtained, the proposed process for grape pomace and orange peels reutilization constitutes a viable alternative for many companies to revalorize their residues and to reduce their contaminant capacity.

Statistical optimization of culture medium for neutral protease production by Aspergillus oryzae. Comparative study between solid and submerged fermentations on tomato pomace

A comparative study of the production of neutral protease was carried out by the cultivation of Aspergillus oryzae NRRL 2220 in solid-state fermentation (SSF) and submerged fermentation (SmF) using tomato pomace based medium. For this purpose, medium optimization was achieved using two experimental designs. The first, corresponded to the Plackett and Burman design with N=8 experiments and k=N−1 factors; five real (wheat bran, casein, NH4NO3, NaCl and ZnSO4) and two errors. Statistical analysis of the results allowed the selection of two factors having a significant effect on enzyme production (casein and NaCl in SSF, wheat bran and NaCl in SmF). Optima of the selected factors have been determined through a second experimental design, the central composite design of Box and Wilson with two factors; 19.79g/L casein and 0.92g/L NaCl for SSF and 17.92g/L wheat bran and 1.18g/L NaCl for SmF were found. The optimal production time of the neutral protease determined from the kinetic study was 96h leading to 21309U/g in SSF and 2343.5U/g in SmF. The comparison of the proteolytic activities of the optimized media demonstrated a ratio of 9 between SSF and SmF, showing the efficiency of the solid-state fermentation compared to the submerged fermentation. The results confirmed the high biotechnological potential of this fungal strain for neutral protease production in solid-state fermentation. Additionally, the utilization of tomato pomace constitutes an efficient and inexpensive agro industrial substrate for protease production via the SSF approach and a suitable mean for its valorization and to reduce its ecological impact.

Comparative Study between Liquid State Fermentation and Solid State Fermentation for Production of Endo-1 , 4-Beta-Xylanase by Bacillus Licheniformis

Comparative Study between Liquid State Fermentation and Solid State Fermentation for Production of Endo-1 , 4-Beta-Xylanase by Bacillus Licheniformis

Micropropagule production from Trichoderma harzianum EGE-K38 using solid-state fermentation and a comparative study for drying methods

In this study, Trichoderma harzianum EGE-K38 was used for micropropagule production in solid-state fermentation. Various inexpensive agricultural co-products including wheat bran, sawdust, rice straw, hazelnut shell, grape marc, and cotton seed cake were tested as natural substrates, and zeolite was tested as an inert support for micropropagule production. Several parameters were determined to obtain maximum micropropagule production: the effects of various nitrogen sources, initial moisture content, initial pH, incubation temperature, and incubation time. Maximum micropropagule count achieved was (1.30 ± 0.68) × 10^{10} cfu/g dry substrate with a wheat bran-malt sprout mixture (3:2), at 28 °C, an initial moisture content of 70% (w/w), and an initial pH of 5.8 ± 0.3 after 4 days of cultivation. In zeolite-based medium, a maximum micropropagule count of (5.12 ± 0.61) × 10^8 cfu/g dry inert support was achieved. Optimized parameters were used in a higher scale where micropropagules were produced in trays using a wheat bran-malt sprout medium and harvested to determine the drying conditions in both lyophilization and oven-drying. It was found that up to 97% of micropropagules retained their viability with glycerol as a protectant after 1 day of oven-drying at 40 °C.

Antioxidant Properties of Fruiting Bodies, Mycelia, and Fermented Products of the Culinary-Medicinal King Oyster Mushroom, Pleurotus eryngii (Higher Basidiomycetes), with High Ergothioneine Content

The culinary-medicinal king oyster mushroom Pleurotus eryngii is known to contain ergothioneine, and its products, including fruiting bodies, mycelia, and solid-state fermented products (adlay and buckwheat), were prepared to study their antioxidant properties. Fruiting bodies, regular and Hi-Ergo mycelia, and fermented products contained 2.05, 1.68, 5.76, 0.79-0.80 mg/g of ergothioneine, respectively. On the basis of the results obtained, P. eryngii products had effective antioxidant activity, reducing power, and scavenging ability on 1,1-diphenyl-2-picrylhydrazyl radicals and chelating ability on ferrous ions. Hi-Ergo mycelia was the most effective in the first 3 antioxidant properties in addition to its ergothioneine content. In addition, fruiting bodies were more effective in all antioxidant properties than regular mycelia. For ethanolic and hot water extracts from mycelia and fruiting bodies, the correlation coefficients between total phenol contents and each antioxidant attribute were 0.483-0.921. Overall, P. eryngii products with high amounts of ergothioneine could be used beneficially as a functional food.

Culture Condition Improvement for Phytase Production in Solid State Fermentation by Aspergillus ficuum Using Statistical Method

The effective factors on phytase production by Aspergillus ficuum PTCC 5288 were studied using solid-state fermentation method in 250 ml shake flask. The effective process parameters on phytase production were identified using Plackett-Burman design. Four factors were identified of different variables, including glucose, moisture, MgSO4, and fermentation time, which were the most significant. The optimum levels of these significant parameters were determined through response surface methodological approach as follows: 10.14% glucose, 62.69% moisture, 0.46% MgSO4 and 119.23 h. The maximum predicted amount of phytase was 24.33 U/gds and the produced amount of phytase under these conditions was 25.6 U/gds, which indicates the efficacy of the model for prediction of phytase production content under different medium conditions.

Beneficial effect of protracted sterilization of lentils on phytase production by Aspergillus ficuum in solid state fermentation

Water addition to the solid substrate preceding autoclaving increased substrate porosity and phytase production in solid state fermentation. In comparison with dry sterilization, the phytase activity increased 6-, 8.5-, and 10-fold when the autoclaving time was 20, 40, and 60 min, respectively. Autoclaving increased the void space of sterilized lentils, and the increase was 16% higher when water was supplemented to the lentils before sterilization. Image analysis of SEM pictures of the solid substrate showed that water supplementation presterilization portended greater micro-fissure surface area, which also increased with increasing the sterilization time. SEM pictures of the fermentation product showed that fungal growth into the center of the solid substrate was ubiquitous when water was supplemented before sterilization but was absent when water was supplemented post sterilization. Similarly, spore formation on the substrate surface for the presterilization water supplementation samples far exceeded spore formation for samples that received supplementation poststerilization. This evidence suggests that improved mass transfer into the solid substrate resulting from additional pore volume and the formation of micro-fissures on the substrate surface is responsible for the observed gains in phytase productivity in solid state fermentation.

Cellulase Production in Solid-State Fermentation by Marine Aspergillus sp. ZJUBE-1 and Its Enzymological Properties

Cellulase Production in Solid-State Fermentation by Marine <i>Aspergillus</i> sp. ZJUBE-1 and Its Enzymological Properties

Degradation of phorbol esters of Jatropha curcas cake by solid-state fermentation and simultaneous lipase production

Degradation of phorbol esters of Jatropha curcas cake by solid-state fermentation and simultaneous lipase production