REVIEW: CORN COB POTENTIAL FOR APPLICATIONS IN COMMERCIAL PRODUCTS

Post-harvest activities of agricultural products often generate wastes. One of the agricultural wastes that increase every year is corn cobs, which have a high cellulose content and can potentially be used as raw materials for making natural fibers. Therefore, this study aims to examine several potential commercial products from corn cobs. The method used is a literature study by tracing the sources of previous writings. Furthermore, how to process corn cobs waste for the manufacture of natural fibers and commercial products will be discussed. From the previously traced sources in the utilization of corn cobs waste, 4 products were obtained. The results are nano hydrogels based on gamma radiation, activated carbon with a carbonation process, bioethanol using the SSF process, and the use of corn cob cellulose as good-quality brake lining.

Screening Extract EtOAc Sponge Derived Fungi Against Clinical Staphylococcus aureus to Obtain Sustainable Natural Product

The increasing resistance of pathogenic bacteria to various antibiotics worldwide has become a severe problem for medicine and human health. This study aims to determine the antibacterial activity of extract ethyl acetate (EtOAc) produced by sponge-derived fungi as an antibacterial agent. This study obtained nineteen fungal isolates from the marine sponges in Singaraja, Buleleng Bali, Indonesia. The pathogenic bacteria Staphylococcus aureus was obtained from patients at Abdul Moeloek Hospital, Bandar Lampung. The susceptibility test of Staphylococcus aureus was carried out on nine types of commercial antibiotics using the disk diffusion method. The solid-state fermentation (SSF) method on rice media carried the cultivation and co-cultivation of fungi. The bioactivity of the extract was tested against pathogenic bacteria S. aureus. The results of the susceptibility test to antibiotics showed S. aureus resistance to amoxicillin, ciprofloxacin, erythromycin. Showed that extracts A12RF, A05RF, C36RF had inhibitory activity against the growth of S. aureus at a concentration of 0,5mg/mL. These results indicate that co-cultivation can induce fungi to produce different secondary metabolites. This basic information is essential for further studies related to the production of fungal bioactive compounds through the co-cultivation stage in the SSF process.

Agro-Industrial Wastes: A Substrate for Multi-Enzymes Production by Cryphonectria parasitica

This study aims to produce a mix of enzymes through Solid State Fermentation (SSF) of raw materials. Four different, easily available, agro-industrial wastes were evaluated as SSF substrates for enzymes production by Cryphonectria parasitica (Murr.) Barr. environmental strains named CpA, CpB2, CpC4, and CpC7. Among the tested wastes, organic wheat bran for human use and wheat bran for animal feed better supports C. parasitica growth and protease production without any supplements. SDS-PAGE analyses highlighted the presence of three bands corresponding to an extracellular laccase (77 kDa), to the endothiapepsin (37 kDa), and to a carboxylesterase (60.6 kDa). Protease, laccase, and esterase activities by C. parasitica in SSF were evaluated for 15 days, showing the maximum protease activity at day 9 (3955.6 AU/gsf,). Conversely, the best laccase and esterase production was achieved after 15 days. The C. parasitica hypovirulent CpC4 strain showed the highest laccase and esterase activity (93.8 AU/gsf and 2.5 U/gsf, respectively). These results suggest the feasibility of a large-scale production of industrially relevant enzymes by C. parasitica strains in SSF process on low value materials.

High-Solid Loading Enzymatic Hydrolysis of Waste Office Paper for Poly-3-Hydroxybutyrate Production Through Simultaneous Saccharification and Fermentation

Waste paper holds great potential as a substrate for the microbial production of bioplastic (Poly-3-hydroxybutyrate (PHB)). This study aimed to produce PHB by utilizing office paper as a substrate using Cupriavidus necator through batch and fed-batch simultaneous saccharification and fermentation (SSF) approach. For the batch experiment, different loadings of shredded office paper (3, 5 and 10%) with two different pretreatments H2O2 (OPH) and H2O2 and Triton X-100 (OPTH) were carried out. For the fed-batch experiment, paper loading started with 3% and two more additions were made at 36 and 84 h. Both experiments were conducted at 30°C, 200 rpm and pH 7 using 55.5 FPU/g of cellulase and 37.5 CBU/g of β-glucosidase with a fixed amount of nitrogen source. High PHB yield was observed with OPH in all loadings, though the OPHT showed a better hydrolysis. Maximum PHB yield (4.27 g/L) was achieved with 10% OP at six days of fermentation in batch SSF. Whereas, maximum PHB yield (4.19 g/L) was obtained within a shorter time (66 h) in the fed-batch OPH paper. The extracted PHB showed well-matched characteristic features to the standard PHB. Finally, this study proves the feasibility of employing SSF process for PHB production using waste paper as an alternative approach to overcome the shortcoming of the separate hydrolysis and fermentation (SHF) process.

Production of cellulosic ethanol from alkali treated wheat straw using P-SSF process and bioconversion of hemicellulosic fraction into high value products

Background: Lignocellulosic biomass is an attractive resource for production of ethanol because of its abundance and lower cost. The economics of lignocellulosic ethanol production can be improved by enhancing the ethanol titres along with utilisation of waste generated during bioconversion process. Objective: The present study was aimed at development of a bioconversion process for production high concentration of ethanol from alkali treated cellulose rich wheat straw (WS) and utilization of unused hemicellulosic fraction into value added products. Methods: WS was subjected to microwave assisted alkali (MAA) treatment. Scanning electron microscopy and Fourier transform infrared spectroscopy were used to analyse structural changes in untreated and pretreated WS. Bioethanol production from pretreated WS was carried out by pre hydrolysis and simultaneous saccharification and fermentation (P-SSF) process using newly isolated Saccharomyces cerevisisae SM1. Liquid fraction generated during pretreatment was utilised for xylooligosaccharides (XOS) production using indigenously produced endoxylanase. Results: MAA treatment of WS was successful in enriching cellulose content of WS by solubilizing hemicellulose and lignin. Ethanol fermentation by P-SSF method lead to high concentration of ethanol (42.10±1.15 g/L) in 48 h. Ethanol productivity and yield were, 0.88 g/L/h and 69.14%, respectively. It can be predicted that 7.143 tons of raw WS may be required to produce 1 ton of ethanol and for additional revenue 191.93 kg xylitol and 263.58 kg XOS (DP2 - DP5) can also be produced simultaneously. Conclusion: The study has demonstrated the feasibility of a bio-refinery process for production of value added compounds in addition to high ethanol yields.

Bioethanol Production from Cellulose-Rich Corncob Residue by the Thermotolerant Saccharomyces cerevisiae TC-5

This study aimed to select thermotolerant yeast for bioethanol production from cellulose-rich corncob (CRC) residue. An effective yeast strain was identified as Saccharomyces cerevisiae TC-5. Bioethanol production from CRC residue via separate hydrolysis and fermentation (SHF), simultaneous saccharification and fermentation (SSF), and prehydrolysis-SSF (pre-SSF) using this strain were examined at 35–42 °C compared with the use of commercial S. cerevisiae. Temperatures up to 40 °C did not affect ethanol production by TC-5. The ethanol concentration obtained via the commercial S. cerevisiae decreased with increasing temperatures. The highest bioethanol concentrations obtained via SHF, SSF, and pre-SSF at 35–40 °C of strain TC-5 were not significantly different (20.13–21.64 g/L). The SSF process, with the highest ethanol productivity (0.291 g/L/h), was chosen to study the effect of solid loading at 40 °C. A CRC level of 12.5% (w/v) via fed-batch SSF resulted in the highest ethanol concentrations of 38.23 g/L. Thereafter, bioethanol production via fed-batch SSF with 12.5% (w/v) CRC was performed in 5-L bioreactor. The maximum ethanol concentration and ethanol productivity values were 31.96 g/L and 0.222 g/L/h, respectively. The thermotolerant S. cerevisiae TC-5 is promising yeast for bioethanol production under elevated temperatures via SSF and the use of second-generation substrates.

Enzymatic degradation of polysaccharides in Chinese vinegar residue to produce alcohol and xylose

Vinegar residue is a key secondary waste in the brewing industry that is often disposed irresponsibly, due to its large quantity and lack of reasonably effective use, causing environmental pollution issues. NaOH was used to pretreat Chinese vinegar residue, and the reaction products were consumed by the enzyme complex and Saccharomyces cerevisiae 1300 during the stage of simultaneous saccharification and fermentation (SSF). The results show that the optimal pretreatment conditions for Chinese vinegar residue were solid-to-liquid ratio of 1 : 11‏, NaOH concentration of 2.2%, pretreatment temperature of 63 °C, pretreatment time of 80 min, and amount of 4.9 IU g^–1 xylanase. While these optimal conditions allowed more effective enzymatic degradation of the dried vinegar residue and resulted in the total sugar yield of 66.1%. Subsequently, dried vinegar residue and enzyme complex were added into the SSF process four times, and SSF reacted in a shaker at 120 r min^–1 and 37 °C for 120 h, the yields of ethanol and xylose were 31.4% and 18.5%, respectively. Therefore, the method of Chinese vinegar residue for alcohol and xylose production by SSF was proved.

Conversion of Brewers’ Spent Grain into Proteinaceous Animal Feed using Solid State Fermentation

Brewers’ Spent Grain (BSG) represents the 85% of the total residue produced during the beer brewing process, with a global annual production volume exceeding the 30 Mtons. Study herein concerns the application of solid state fermentation (SSF) process for the efficient transformation of BSG into high nutritional value animal feed. The investigated SSF procedure was initiated by Pleurotus ostreatus, which constitutes a natural source of β-glucans and metabolites (vitamins, nutrients). Thus, it is possible to reduce the environmental impacts caused by BSG production and simultaneously contribute to the tackling of proteinaceous animal feed shortage observed during the last decade. The method developed resulted in a significant increase of protein content by 49.49%, a 10-fold increase of their 1,3 − 1,6 β-glucans content and a respective reduction of cellulose content by 11.42%. The application of this method is expected to provide a solid background for the utilization of BSG as substrate for fungi initiated SSF, a bioprocess allowing the significant reduction of the environmental impact caused by the beer brewing industry and simultaneously produce animal feed with high protein content and nutritional characteristics suitable for fulfilling animals’ nutritional needs and improving their welfare.

Optimization of Solid State Fermentation of Mixed-Culture of Penicillium Consortium for Cellulase and Lytic Polysaccharide Monooxygenases Production

In order to produce higher titre of cellulolytic enzyme cocktails, present study deals with four Penicillium consortium mixed-culture and to investigate their feasibility of producing higher cellulase and auxiliary enzymes via solid state fermentation (SSF). Among different lignocellulosic waste, rice straw was found to be the most suitable substrate. In addition, the Penicillium consortium in a mixture ratio of 1:1:1:1 which exhibited higher enzyme activity than the monoculture. Nitrogen sources of tryptone had significant influences on cellulase and lytic polysaccharide monooxygenases (LPMOs) production. The highest cellulase and LPMO activities were 16.65 ± 1.83 U/g and 33.87 ± 0.45 U/g, respectively. The SSF process condition used to obtain these activities were at 30 °C during 5 days. These results show that the optimized studied of mixed-cultivation system with Penicillium consortium have potential to be exploiting a complex consortium for the enrichment of cellulolytic enzyme cocktails for bioethanol processes.

Automatic and Intelligent Technologies of Solid-State Fermentation Process of Baijiu Production: Applications, Challenges, and Prospects

Baijiu is the national liquor of China and the world’s most consumed spirit, which is produced using a unique and traditional solid-state fermentation (SSF) process. The development of an automatic and intelligent technology for SSF is more difficult than that for liquid-state fermentation. However, the technological upgrading of the SSF process is crucial for reducing the labor intensity, saving manpower, avoiding the waste of materials and energy, and providing a favorable operation environment for workers; moreover, it provides a great reference value to similar industries. This article reviews the latest application progresses in automatic and intelligent technologies for Baijiu production. The important technical processes are introduced successively, including the production of Jiuqu, SSF, solid-state distillation, storage, and blending. The bottlenecks and challenges are pointed out for automatic and intelligent upgrading of these technical processes. Furthermore, the typical technology application cases in an integrated automatic production line of Baijiu are also summarized. Next, the industrial development status of Baijiu production is compared with those of other liquors in the world. Finally, future development directions are proposed. This review will provide an overall introduction and objective analysis of recent developments and current challenges in Baijiu manufacturing so as to promote the intelligent brewing of Baijiu.