• Fisheries and Aquatic Sciences
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• v.25 no.7
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• pp.357-379
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• 2022

Increased fisheries products have raised by-products that are discarded due to low economic value. In addition, marine by-products are still rich in protein and nutritional value that have biological activities and give benefits to human health. Meanwhile, there is raised pressure for sustainability practices in marine industries to reduce waste and minimize the detrimental effect on the environment. Thus, valorization by-products through bioactive peptide mining are crucial. This review focus on various ways to obtain bioactive peptides from marine by-products through protein hydrolysis, for instance chemical hydrolysis (acid and based), biochemical hydrolysis (autolysis and enzymatic hydrolysis), microbial fermentation, and subcritical water hydrolysis. Nevertheless, these processes have benefits and drawbacks which need to be considered. This review also addresses various biological activities that are favorable in pharmaceutical industries, including antioxidant, antihypertensive, anticancer, anti-obesity, and other beneficial bioactivities. In addition, some potential marine resources of Indonesia for the marine biopeptide from their by-product or undesired marine commodities would be addressed as well.

• YAKHAK HOEJI
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• v.41 no.4
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• pp.480-483
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• 1997

The efficient synthesis of p-(acetylamino)phenylacetic acid(7), a antirheumatic agent, is reported. Methyl phenylacetate(3) was prepared from Friedel- Crafts reaction of benzene with methyl ${\alpha}$-chloro-${\alpha}$-(methylthio)acetate(1) followed by reductive desulfurization with zinc dust in acetic acid. Compound(7) was obtained from 3 by a sequence of nitration, reduction, N-acylation, and hydrolysis.

• Microbiology and Biotechnology Letters
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• v.2 no.2
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• pp.95-101
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• 1974

Studies on the optimum conditions of acid hydrolysis of sweet potato starch cake and its utilization on the production of Saccharomyces cerevisiae as a carbon source were conducted and the results showed as follows; 1.The highest hydrolysis rate, 62.7 ％ of the reducing sugar based on the weight of the dry matter, was obtained when the starch cake was hydrolyzed with 1.0％ of hydrochloric acid at 2.0 kg/$\textrm{cm}^2$ for 30 minutes. 2. But the yeast grew most favorably on the hydrolyzate obtained by treating the starch cake with 0.5％ of hydrochloric acid at 2.0 kg/$\textrm{cm}^2$ for 10 minutes. Reducing sugar content of hydrolyzate was 51.4％. 3. The optimum pH of the culture medium was 7.0, Cell growth reached to the maximum at 36 hours of cultivation time. 4. According to the vitamin requirement tests, Ca-pantothenate was found to be a promoting factor for the growth of the yeast cells. 5. "Gluten acid hydrolyzate" was most effective to the cell growth when added to the medium at the concentration of 0.1％ as a nitrogen source. 6. Sacch. cerevisiae could assimilate the sugars in the hydrolyzate about 89.1％, and the yields of the yeast cells showed 23.2mg/ml of culture medium.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.270-270
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• 2017

Brown rice flour (BRF) was treated with different carbohydrases (Viscozyme, Termamyl, Celluclast, AMG, Ultraflo, and Pentopan), and then aqueous alcoholic extracts (70% ethanol) from the treated RBF were examined for their phenolic compositions and antioxidant activities (ABTS and DPPH radical scavenging activity). All the carbohydrases tested induced significant increases in ABTS radical scavenging activity (2.1-3.0 times). Moreover, These enzymes increased the amount of extractable free phenolic acids by 10-15 times, especially for ferulic and p-coumaric acid. Among the enzymes tested, Pentopan which was active in arabinoxylan hydrolysis appeared to be most effective in increasing the free phenolic acid content and ABTS radical scavenging activity than other enzymes. Enzymatic hydrolysis of cell wall polysaccharides in BRF could be used as an effective procedure for raising the amount of extractable phenolic acids and thus increasing the antioxidant activity of BRF extract.

• Journal of the Korean Applied Science and Technology
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• v.25 no.3
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• pp.341-346
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• 2008

Cellulose nanofibers from microfibril cellulose (MFC) was prepared by hydrobromic acid (HBr) treatment at different concentrations. Polyvinyl alcohol (PVA) composite films at various loading level of nanofibers were manufactured by a film casting method. The analysis of degree of polymerization (DP), crystallinity ($X_c$) and molecular weight ($M_w$) of cellulose after acid treatment was conducted. The mechanical and thermal properties of the cellulose nanofibers reinforced PVA films were characterized using tensile tests and thermogravimetric analysis (TGA). The DP and $M_w$ of MFC by HBr hydrolysis considerably decreased, but $X_c$ showed no significant change. After acid hydrolysis, the diameter of cellulose nanofibers was in the range of 100 to 200 nm. The thermal stability of the films was steadily improved with the increase of nanofiber loading. There was a significant increase in the tensile strength of PVA composite films with the increase in MFC loading. Finally, 5 wt.% nanofiber loading exhibited the highest tensile strength and thermal stability of PVA composite films.

• Journal of Microbiology and Biotechnology
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• v.2 no.1
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• pp.56-65
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• 1992

The complete nucleotide sequence of the Bacillus circulans F-2 RSDA gene, coding for raw starch digesting a-amylase (RSDA), has been determined. The RSDA structure gene consists of an open reading frame of 2508 bp. Six bp upstream of the translational start codon of the RSDA is a typical gram-positive Shine-Dalgarno sequence and the RSDA encodes a preprotein of 836 amino acids with an Mr of 96, 727. The gene was expressed from its own regulatory region in E. coli and two putative consensus promoter sequences were identified upstream of a ribosome binding site and an ATG start codon. Confirmation of the nucleotide sequence was obtained and the signal peptide cleavage site was identified by comparing the predicted amino acid sequence with that derived by N-terminal analysis of the purified RSDA. The deduced N-terminal region of the RSDA conforms to the general pattern for the signal peptides of secreted prokaryotic proteins. The complete amino acid sequence was deduced and homology with other enzymes was compared. The results suggested that the Thr-Ser-rich hinge region and the non-catalytic domain are necessary for efficient adsorption onto raw substrates, and the catalytic domain (60 kDa) is necessary for the hydrolysis of substrates, as suggested in previous studies (8, 9).

• Journal of Environmental Science International
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• v.19 no.10
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• pp.1247-1256
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• 2010

Since biodiesel as bioenergy is defined as ester compounds formed by esterification of animal/vegetable oils, in this study three vegetable cooking oils (market, waste and refined waste ones) were esterified by reactions of alkali catalyst and immobilized enzyme. The fatty acid composition of the formed ester compounds was analyzed to investigate the feasibility of biodiesel production. By lipolysis (i.e, hydrolysis of Triglyceride (TG)), all three vegetable oils used in this study were found to produce Diglyceride (DG), Monoglyceride (MD) and Fatty acid ethylester (FAEE). However, the amount of produced FAEE (which can be used as an energy source) was in the increasing order of market cooking oil, waste one and refined waste one. With NaOH catalyst, FAEE was produced about 24.92, 17.63 and 11.31 % for the respective oils while adding Lipozyme TL produced FAEE about 43.54, 38.16 and 24.47 %, respectively. This indicates that enzyme catalyst is more effective than alkali one for transesterification. In addition, it was found that the composition of fatty acids produced by hydrolysis of TG was unchanged with alkali and immobilized enzyme reactions. Thus it can be expected that stable conditions remain in the course of mixing with gasoline whose composition is similar to that of the fatty acids.

• Journal of Environmental Health Sciences
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• v.31 no.4 s.85
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• pp.294-300
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• 2005

Food waste can be a valuable carbon source in biological nutrient removal (BNR) systems because of high C/N and C/P ratios. However, food waste should be pretreated to promote its hydrolysis rate because hydrolysis reaction would be a rate-limiting step. This study investigates the influence of the enzymatic pretreatment on acid fermentation of food waste. Solubilization of particulate matter in food waste by using commercial enzymes was examined. The acidification efficiency and the volatile fatty acids (VFAs) production potential of enzymatically pretreated food waste were also examined. The highest volatile suspended solids (VSS) reduction was obtained with an enzyme mixture ratio of 1:2:1 of carbohydrase:protease:lipase. An optimum enzyme dosage for solubilization of food waste was $0.1\%$(V/V) with the enzyme mixture ratio of 1:2:1. In the acid fermentation of enzymatically pretreated food waste, $0.1\%$(V/V) enzyme mixture dosage for pretreatment result in the maximum VFAs production and the best VFAs fraction in soluble COD(SCOD). The VFAs production at this addition level was 3.3 times higher than that of no-enzyme added fermenter. The dominant VFAs present was n-butyrate followed by acetate.

• Journal of the Korean Wood Science and Technology
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• v.41 no.2
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• pp.111-122
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• 2013

The steam explosion-chemical pretreatment is a more effective wood pretreatment technique than the conventional physical pretreatment by accelerating reactions during the pretreatment process. In this paper, two-stage pretreatment processes of hardwood were investigated for its enzymatic hydrolysis and the succinic acid yield from the pretreated solid. The first stage pretreatment was performed under conditions of low severity to optimize the amount of solid recovery. In the second stage pretreatment washed solid material from the first stage pretreatment step was impregnated again with chemical (alkaline or chlorine-based chemicals) to remove a portion of the lignin, and to make the cellulose more accessible to enzymatic attack. The effects of pretreatment were assessed by enzymatic hydrolysis and fermentation, after the two stage pretreatments. Maximum succinic acid yield (16.1 g $L^{-1}$ and 77.5%) was obtained when the two stage pretreatments were performed at steam explosion -3% KOH.

• Archives of Pharmacal Research
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• v.17 no.1
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• pp.17-20
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• 1994

Friedel-Crafts reaction of fluorene with methyl ${\alpha}$-chloro-${\alpha}$-(methylthio)acetate 1 gave methyl $\alpha$-methylthio-2-fluoreneacetate 2. Cicloprofen 8, a potent antiinflammatory agent, was prepared by methylation of 2 followed by reductive desulfurization of methyl 2(2-fluorenyl)-2-(methylthio)propionate 6 and hydrolysis of methyl 2-(2-fluorenyl)propionate 7.