• Journal of Microbiology and Biotechnology
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• v.28 no.9
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• pp.1511-1516
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• 2018

In this study, we investigated Indole-3-acetic acid (IAA) production by a rice phylloplane bacteria, Enterobacter sp. DMKU-RP206, using sweet whey as a feed stock instead of lactose. We succeeded in using sweet whey for Enterobacter sp. DMKU-RP206 to produce 3,963.0 mg IAA/l with the optimal medium containing 1.48% sweet whey, 1.42% yeast extract and 0.88% $\text\tiny{L}$-tryptophan. The medium pH was adjusted to 6 and the culture conditions were shaking at 200 rpm on an orbital shaker at $30^{\circ}C$ for 3 days. We also evaluated the effect of IAA in culture filtrates of Enterobacter sp. DMKU-RP206 on the promotion of jasmine rice growth in a pot experiment. Compared with the negative control (without IAA), the result showed that biosynthetic IAA produced by Enterobacter sp. DMKU-RP206 significantly increased the growth of jasmine rice (Oryza sativa L. cv. KDML105) in terms of length and dry weight of shoot. This work thus reveals the impact of IAA produced by Enterobacter sp. on the promotion of jasmine rice growth.

• Food Science and Biotechnology
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• v.16 no.5
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• pp.836-842
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• 2007

In this study, we investigated the effects of heating ($80^{\circ}C$, 30 min) on the physicochemical and functional attributes of acid (cottage) and sweet (Edam and Cheddar) whey powders. The water holding capacity (WHC) of the whey powders was not affected by heating or pH value. The heated Cheddar whey powder had a significantly lower (p<0.05) WHC than that of the other wheys. Heating detrimentally impacted the emulsifying and foaming properties, On the other hand, heating significantly enhanced the heat stabilities (HS) of all powders, This was best demonstrated at the acidic pH values of 3.0 and 4.5, where the HS increased by 57 and 53, 181 and 167, and 31 and 48%, for the cottage, Edam, and Cheddar, respectively. Overall, this data provides useful insights into the manufacture of pasteurization and retort-stable whey powders.

• Korean Journal of Food Science and Technology
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• v.28 no.1
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• pp.99-104
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• 1996

Carbohydrate-free caseinomacropeptide (CMP) was isolated from the sweet whey powder by a precipitation method using 12% trichloroacetic acid. The yield of carbohydrate-free CMP was 2.7 g from 100 g sweet whey powder. The electrophoretic pattern and the amino acid analysis of CMP showed that isolated CMP was quite pure, indicating the precipitation with 12% trichloroacetic acid was very effective for isolating carbohydrate-free CMP from the sweet whey powder. Trypsin, covalently immobilized on pore glass beads by carbodiimide (EDC) method, was 20mg per 1g glass beads. CMP was almost completely hydrolyzed by soluble trypsin in 24hr, but not by immobilized trypsin. The tryptic hydrolysates were fractionated on a Bio-Gel P 4 column $(1.5{\times}120\;cm)$and separated peptides were tested for their capacities to inhibit platelet aggregation using a aggregometer. The hydrolysate obtained from CMP after 24hr digestion by immobilized trypsin showed the highest activity.

• Microbiology and Biotechnology Letters
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• v.36 no.1
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• pp.61-66
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• 2008

The proteins in whey are separated and used as food additives. The remains (mainly lactose) are spray-dried to produce sweet whey powder, which is widely used as an additive for animal feed. Sweet whey powder is also used as a carbon source for the production of valuable products such as polysaccharides. Glucose, fructose, galactose, and sucrose as asupplemental carbon source were evaluated for the production of PS-7 from Azotobacter indicus var. myxogenes L3 grown on whey based MSM media. Productions of PS-7 with 2% (w/v) fructose and sucrose were 2.05 and 2.31g/L, respectively. The highest production of PS-7 was 2.82g/L when 2% (w/v) glucose was used as the carbon source. Galactose showed low production of PS-7 among the carbon sources tested. The effects of various carbon sources addition to whey based MSM medium showed that glucose could be the best candidate for the enhancement of PS-7 production using whey based MSM medium. To evaluate the effect of glucose addition to whey based media on PS-7 production, fermentations with whey and glucose mixture (whey 1, 2, 3%; whey 1% + glucose 1%, whey 1% + glucose 2% and glucose 2%, w/v) were carried out. Significant enhancement of PS-7 production with addition of 1% (w/v) and 2% (w/v) glucose in 1% (w/v) whey media was observed. The PS-7 concentration of 2% glucose added whey lactose based medium was higher than that of 1% glucose addition, however, the product yield $Y_{p/s}$ was higher in 1% glucose added whey lactose based MSM medium. Therefore, the optimal condition for the PS-7 production from the Azotobacter indicus var.myxogenes L3, was 1% glucose addition to 1% whey lactose MSM medium.

• Journal of the Korean Society of Food Science and Nutrition
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• v.30 no.6
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• pp.1068-1075
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• 2001

Effect of soybean-curd whey on the dongchimi fermentation was investigated by measuring physicochemical and sensory characteristics during fermentation at 1$0^{\circ}C$. Dongchimi was prepared with various levels (0, 2, 5, and 10%) of soybean-curd whey. During fermentation, whereas salt concentrations of dongchimi liquid (1.1 ~ 2.0%) were similar among treatments, greater decrease in pH, but greater increase of total acidity, reducing sugar content, number of lactic acid bacteria and turbidity were observed in dongchimi with soybean-curd whey than those of control from the 2nd to the 9th day of fermentation. But at the 16th day of fermentation, acidity, turbidity and number of lactic acid bacteria of dongchimi with soybean-curd whey were similar to those of control. Reducing sugar content of soybean-curd whey addition groups maintained higher than that of control. The Hunter color L value decreased gradually and that of dongchimi with soybean-curd whey was lower than that of control. b value of control increased, but soybean-curd whey addition groups decreased during fermentation. Hardness and fracturability, determined by texture analyser, were higher in soybean-curd whey addition groups than control. Sensory evaluation showed that the scores of turbidity, sweet taste, savory taste, hardness and over-all preference were significantly higher in soybean-curd whey addition groups than control (p<0.05) ; the highest with 5% soybean-curd whey addition followed by 2% addition. dongchimi with 5% soybean-curd whey addition was the most preferable one with the score of 6.5.

• Asian-Australasian Journal of Animal Sciences
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• v.13 no.5
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• pp.619-624
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• 2000

Low-quality roughages [banana wastes (B), wheat straw (WS) and dried broiler litter (BL)] were ensiled using either sweet whey (W) or diluted molasses (M) as rehydration media to study their effects on milk yield, milk composition and some parameters of blood plasma. The feeding trial involved 25 lactating buffaloes in five groups (five animals each). Buffaloes as control animals received diets of concentrate feed mixture, rice straw and wastelages (70:30:00). In the other 4 treatments, the wastelages replaced 50% of rice straw in the control diets. The wastelages were BL:B:M(3:2:10) (T1), BL:WS:M (3:2:10) (T2), BL:B:W (3:2:10) (T3) and BL:WS:W (3:2:10) (T4) on a fresh matter basis, during the 1st 17 weeks of lactation period. Results indicated that feeding lactating buffaloes on wastelages resulted in slightly higher (p>0.05) milk yield, 4% fat-corrected-milk yield and feed efficiency, and slightly lowered (p>0.05) contents of milk total solids, fat and protein. Wastelages, especially BL-B-M, increased (p<0.05) milk non-protein-nitrogen and ash contents and plasma urea, GOT and GPT. The results demonstrate that banana plant wastes with some additives in silage form may be good untraditional roughage for lactating buffaloes without any adverse effect on milk production.

• Journal of Dairy Science and Biotechnology
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• v.35 no.2
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• pp.135-142
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• 2017

This study was conducted to evaluate the quality characteristics of yogurt containing 5.0%, 10.0%, and 20.0% rice-wine (RW), which was added during the preparation of yogurt. Changes in pH, total titratable acidity (TA), bacterial lactic acid, yeast population, viscosity, whey separable phenomenon, and cumulative gas production were monitored during the fermentation and storage of yogurt. The pH was decreased following all treatments, and TA and viscosity were gradually increased during fermentation. The pH of RW yogurt was lower than that of the control sample, and TA was higher than the control during fermentation. The viscosity of yogurt containing 5.0% and 10.0% RW yogurt was higher than that of the control sample at 0~6 h. Cumulative gas production and whey separable phenomenon increased as the amount of RW added increased during fermentation. Viscosity was higher in control yogurt than in RW yogurt during storage. The total acceptability, texture, odor, color, sweet taste, and yogurt taste were higher in the control than in all RW groups.

• Journal of Microbiology and Biotechnology
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• v.33 no.11
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• pp.1531-1541
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• 2023

Lipase is a well-known and highly in-demand enzyme. During the last decade, several lipase optimization studies have been reported. However, production costs have always been a bottleneck for commercial-scale microbial enzyme production. This research aimed to optimize the conditions for lipase production by Limtongozyma siamensis DMKU-WBL1-3 via a One-Factor-At-a-Time (OFAT) approach combined with statistical methods while using a low-cost substrate. Results suggest that low-cost substrates can be substituted for all media components. An optimal medium was found, using response surface methodology (RSM) and central composite design (CCD), to consist of 0.50% (w/v) sweet whey, 0.40% (w/v) yeast extract (food grade), and 2.50% (v/v) palm oil with the medium pH adjusted to 4 under shaking flask cultivation. From an economic point of view, this work was successful in reducing production costs while increasing lipase productivity. The medium costs were reduced by 87.5% of the original cost while lipase activity was increased by nearly 6-fold. Moreover, lipase production was further studied in a 2-L stirred-tank fermentor. Its activity was 1,055.6 ± 0.0 U/ml when aeration and agitation rates were adjusted to 1 vvm and 170 rpm, respectively. Interestingly, under this optimal lipase production, the yeast showed accumulated lipids inside the cells. The primary fatty acid is a monounsaturated fatty acid (MUFA) that is typically linked to health benefits. This study hence reveals promising lipase production and lipid accumulation by L. siamensis DMKU-WBL1-3 that are worthy of further study.