Pairote Wongputtisin

Use of Bacillus subtilis isolates from Tua-nao towards nutritional improvement of soya bean hull for monogastric feed application

Soya bean hull (SBH) is a cheap and high‐fibre content feed ingredient that obtained after soya bean oil extraction. Microbial fermentation was expected to improve SBH qualities before applying to animals, especially monogastric animals. Two bacterial strains, Bacillus subtilis MR10 and TK8 that were isolated from Tua‐nao, a traditional fermented soya bean in northern Thailand, were used for fermented soya bean hull (FSBH) production. Both could easily grow at 37°C in SBH as the sole substrate. MR10 produced the highest β‐mannanase activity (400 U g−1 SBH) on day 2, while TK8 produced the highest cellulase activity (14·5 U g−1 SBH) on day 3. After fermentation, the nutritional quality of SBH was obviously improved by an increase in soluble sugars, soluble proteins, crude protein and crude lipid, and a decrease in the content of raffinose family oligosaccharides. Scavenging activity (%) of SBH against ABTS radical cation was also increased from 14 to 27 and 20% by MR10 and TK8 fermentation, respectively. According to the GRAS property of these both strains and various improvements of nutritional values, the fermented SBH proved to be a potential feed ingredient, especially for the monogastric animals.

Optimization of soybean processing into kinema, a Bacillus‐fermented alkaline food, with respect to a minimum level of antinutrients

Optimization of traditional processing of soybeans using response surface methodology (RSM) to achieve a minimum level of antinutritional factors (ANFs) in kinema.

Screening and selection of Bacillus spp. for fermented corticate soybean meal production

To screen and select the Bacillus spp. from Tua‐nao of northern Thailand for fermented corticate soybean meal (FCSBM) production.

Transferase Activity of Lactobacillal and Bifidobacterial β-Galactosidases with Various Sugars as Galactosyl Acceptors

The β-galactosidases from Lactobacillus reuteri L103 (Lreuβgal), Lactobacillus delbrueckii subsp. bulgaricus DSM 20081 (Lbulβgal), and Bifidobacterium breve DSM 20281 (Bbreβgal-I and Bbreβgal-II) were investigated in detail with respect to their propensity to transfer galactosyl moieties onto lactose, its hydrolysis products d-glucose and d-galactose, and certain sugar acceptors such as N-acetyl-d-glucosamine (GlcNAc), N-acetyl-d-galactosamine (GalNAc), and l-fucose (Fuc) under defined, initial velocity conditions. The rate constants or partitioning ratios (kNu/kwater) determined for these different acceptors (termed nucleophiles, Nu) were used as a measure for the ability of a certain substance to act as a galactosyl acceptor of these β-galactosidases. When using Lbulβgal or Bbreβgal-II, the galactosyl transfer to GlcNAc was 6 and 10 times higher than that to lactose, respectively. With lactose and GlcNAc used in equimolar substrate concentrations, Lbulβgal and Bbreβgal-II catalyzed the formation of N-acetyl-allolactosamine with the highest yields of 41 and 24%, respectively, as calculated from the initial GlcNAc concentration.

X-ray-induced mutation of Bacillus sp. MR10 for manno-oligosaccharides production from copra meal

ABSTRACT The present study demonstrates the effectiveness of X-ray radiation in strain improvement for defective lipase production by Bacillus sp. MR10 for further application in the fermentative production of manno-oligosaccharides (MOS) from agricultural by-product, defatted copra meal (DCM). The mutants obtained were screened based on their defective lipase activity together with their β-mannanase production performance. Among 10 selected mutants, the strain M7 was the highest promising mutant regarding the smallest lipase activity (0.05 U/ml) and the retained β-mannanase activity similar to the parental strain (22 U/ml) were detected. The mutant M7 effectively hydrolyzed DCM to MOS with low-degree of polymerization (DP) oligomers including mannotriose (M3), mannotetraose (M4), and mannopentose (M5) as the main products. Although the pattern of DCM hydrolysis products of mutant M7 was distinctly different from wild type, the biochemical and catalytic properties of purified β-mannanase of mutant were similar to those of wild type. Both purified β-mannanases with apparent molecular mass of 38 kDa displayed optimal activity at pH 5–7 and 45–55°C. Co2+ and Hg2+ nearly completely inhibited activities of both enzymes, whereas Ba2+, Fe3+, and 2-mercaptoethanol obviously activated enzyme activities. Both enzymes showed high specificity for locust bean gum, konjac mannan, DCM, and guar gum. Thus, the mutant M7 has a potential for commercial production of high-quality MOS from low-cost DCM for further application in the feed industry.

Selection of Low-Cost Culture Medium for the Production of Bacterial Protease for Application in Para Rubber Manufacturing

Protease enzyme produced from Bacillus sp., isolated from northern Thai fermented food, has been accepted for its ability in degradation of rubber allergens. Protease-treated latex can be used in the production of several medical rubber products, i.e. surgery glove, condom, feeding tube, etc. However, production cost of this protease was considered as the main cost of medical rubber product manufacturing. Therefore, the aim of this study was to select low-cost medium for protease production instead of nutrient broth (NB), a commercial culture medium. The results showed that Bacillus sp. could grow in soybean meal (SBM) and skim milk medium similar to NB. Moreover, protease could be produced at 52.2, 31.1 and 25 unit/ml with the specific activity at 16.41, 9.08 and 8.16 in NB, SBM and skim milk medium, respectively. However, SBM was selected in this study because its unit cost was lower than the others. Ability in degradation of rubber elongation factor (REF), a major allergenic protein in Para rubber latex, by protease produced in SBM medium was tested. It was found that REF was degraded completely similar to that produced by NB. Thus, SBM could be used as an effective low-cost culture medium for protease production.

Biomass Production of Spirulina platensis in Medium Containing Effluent from Para Rubber Sheet Manufacturing Process

Effluent obtained from Para rubber sheet processing contains many chemical components, i.e., ammonia, nitrite, nitrate, phosphate, sugar, protein, and other organic compounds. Thus, it was subjected to be applied as nutritional source for microbial media. After pH, hardness and suspended solids of effluent were treated using NaOH, lime, and soda ash. A possibility of the treated effluent for algal Spirulina platensis biomass production was studied. The results revealed that growth of S. platensis decreased when standard culture medium was supplemented with a higher ratio of effluent. At 20 % (v/v) substitution of effluent yielded an acceptable algal biomass comparing to at the other ratio. Moreover, it was found that specific growth rate (Day−1) and doubling time (Day) of S. platensis when cultured in 20 % (v/v) substituted medium were at 0.09 ± 0.012 and 8.0 ± 1.6, respectively, while those when cultured in standard medium were 0.15 ± 0.008 and 4.57 ± 0.25, respectively. However, crude protein content of single cell proteins obtained from both medium was not different (p > 0.05).