• Asian-Australasian Journal of Animal Sciences
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• 제21권10호
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• pp.1495-1500
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• 2008

In an attempt to develop a probiotic formulation for poultry feed, a number of lactic acid bacteria (LAB) were isolated from chicken intestinal specimens and a series of in vitro experiments were performed to evaluate their efficacy as a potential probiotic candidate. A total of 650 LAB strains were isolated and screened for their antagonistic potential against each other. Among all the isolates only three isolates (TMU121, 094 and 457) demonstrated a wide spectrum of inhibition and were thus selected for detailed investigations. All three selected isolates were able to inhibit the growth of E. coli and Salmonella species, although to variable extent. The nature of the inhibitory substance produced by the isolates TMU121 and 094 appeared to be associated with bacteriocin, as their activity was completely lost after treatment with proteolytic enzymes, while pH neutralization and catalase enzyme had no effect on the residual activity. In contrast, isolate TMU457 was able to resist the effect of proteolytic enzymes while pH neutralization completely destroyed its activity. Attempts were made to study the acid, bile tolerance and cell surface hydrophobicity of these isolates. TMU121 showed high bile salt tolerance (0.3%) and high cell surface hydrophobicity compared to the other two strains studied, while TMU094 appeared the most pH resistant strain. Based on these results, the three selected LAB isolates were considered as potential ingredients for a chicken probiotic feed formulation and were identified to species level based on their carbohydrate fermentation pattern by using API 50CH test kits. The three strains were identified as Lactobacillus fermentum TMU121, Lactobacillus rhamnosus TMU094, and Pediococcus pentosaceous TMU457.

• Preventive Nutrition and Food Science
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• 제7권4호
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• pp.397-404
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• 2002

Soybean curd residue (SCR) was fermented by lactic acid bacteria, Lactobacillus rhamnosus LS and Entercoccus faecium LL, isolated from SCR. The pH, titratable acidify and viable cell counts were determined from the fermented SCR to evaluate the lactic acid production and growth of lactic acid bacteria. Optimal amounts of pretense enzyme and glucose, and ideal fermentation time for SCR fermentation were estimated by response surface methodology (RSM). Raw SCR fermented by indigenous microorganisms had 0.78 % titratable acidity, The acid production in SCR fermented by L. rhamnosus LS was greatly enhanced by the addition of glucose and lactose. However only glucose increased acid production by Ent. faecium LL. The proof test of SCR fermentation demonstrated that similar results for titratable acidity, tyrosine content and viable cell counts to that predicted could be obtained by the at optimized fermentation conditions. In the presence of 0.029 % (w/w) pretense enzyme and 0.9% (w/w) glucose, the SCR fermented by Ent. faecium LL showed 1.07% (w/v) of titratable acidity, 1.02 mg% tyrosine content and 2$\times$10$^{9}$ (cfu/g) of viable cell counts. With the SCR fortified with 0.033% pretense enzyme and 1.7% glucose, L. rhamnosus LS showed 1.8% (w/v) of titratable acidity, 0.92 mg% of tyrosine content and 2$\times$10$^{9}$ (cfu/g) of viable cell counts.

• Asian-Australasian Journal of Animal Sciences
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• 제27권6호
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• pp.898-906
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• 2014

The objective of this study was to investigate differences in the faecal microbial composition among Lantang, Bama, Erhualian, Meishan, Xiaomeishan, Duroc, Landrace, and Yorkshire sows and to explore the possible link of the pig breed with the gut microbial community. Among the sows, the Meishan, Landrace, Duroc, and Yorkshire sows were from the same breeding farm with the same feed. Fresh faeces were collected from three sows of each purebred breed for microbiota analysis and volatile fatty acid (VFA) determination. Denaturing gradient gel electrophoresis (DGGE) analysis revealed that samples from Bama, Erhualian, and Xiaomeishan sows, which from different farms, were generally grouped in one cluster, with similarity higher than 67.2%, and those from Duroc, Landrace, and Yorkshire sows were grouped in another cluster. Principal component analysis of the DGGE profile showed that samples from the foreign breeds and the samples from the Chinese indigenous breeds were scattered in two different groups, irrespective of the farm origin. Faecal VFA concentrations were significantly affected by the pig breed. The proportion of acetate was higher in the Bama sows than in the other breeds. The real-time PCR analysis showed that 16S rRNA gene copies of total bacteria, Firmicutes and Bacteroidetes were significantly higher in the Bama sows compared to Xiaomeishan and Duroc sows. Both Meishan and Erhualian sows had higher numbers of total bacteria, Firmicutes, Bacteroidetes and sulphate-reducing bacteria as compared to Duroc sows. The results suggest that the pig breed affects the composition of gut microbiota. The microbial composition is different with different breeds, especially between overseas breeds (lean type) and Chinese breeds (relatively obese type).

• Mycobiology
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• 제36권4호
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• pp.249-254
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• 2008

Minimal growth inhibitory concentrations (MICs) of chitosan acetate (M.W. 60 kDa) on heterotrophic bacteria (strains MK1, S, and R) isolated from the soft-rotten tissues of Neungee mushroom (Sarcodon aspratus) were measured. The slimy substance produced by the MK1 strain was responsible for the diseased mushroom’s appearance. The S and R strains were members of the Burkholderia cepacia complex. These strains showed different levels of susceptibility toward chitosan acetate. The MIC of chitosan acetate against the MK1 and S strains was 0.06%. The MIC against the R strain was greater than 0.10%. Survival fractions of the MK1 and S strains at the MIC were $3\;{\times}\;10^{-4}$ and $1.4\;{\times}\;10^{-3}$ after 24 h, and $2\;{\times}\;10^{-4}$ and $7\;{\times}\;10^{-4}$ after 48 h, respectively. Survival fractions of the R strain after 24 and 48 hr at 0.1% chitosan acetate were $1\;{\times}\;10^{-2}$ and $6.9\;{\times}\;10^{-3}$, respectively. Compared to the MK1 and S strains, the low susceptibility of the R stain towards chitosan acetate could be due to the ability of the R strain to utilize chitosan as a carbon source. Thirty-eight percent of Neungee pieces treated in a 0.06% chitosan acetate solution for $2{\sim}3$ second did not show any bacterial growth at 4 days, whereas bacterial growth around untreated mushroom pieces occurred within 2 days. These data suggest that chitosan acetate is highly effective in controlling growth of indigenous microorganisms on Neungee. The scanning electron micrographs of the MK1 strain treated with chitosan revealed a higher degree of disintegrated and distorted cellular structures.

• Ocean and Polar Research
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• 제27권2호
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• pp.205-214
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• 2005

From ancient Antarctic glacier ice, we extracted total genomic DNA that was suitable for prokaryotic 16S rDNA gene cloning and sequencing, and bacterial artificial chromosome (BAC) library and end-sequencing. The ice samples were from the Dry Valley region. Age dating by $^{40}Ar/^{39}Ar$ analysis on the volcanic ashes deposited in situ indicated the ice samples are minimum 100,000-300,000 yr (sample DLE) and 8 million years (sample EME) old. Further assay proved the ice survived freeze-thaw cycles or other re-working processes. EME, which was from a small lobe of the basal Taylor glacier, is the oldest known ice on Earth. Microorganisms, preserved frozen in glacier ice and isolated from the rest of the world over a geological time scale, can provide valuable data or insight for the diversity, distribution, survival strategy, and evolutionary relationships to the extant relatives. From the 16S gene cloning study, we detected no PCR amplicons with Archaea-specific primers, however we found many phylotypes belonging to Bacteria divisions, such as Actinobacteria, Acidobacteria, Proteobacteria $({\alpha},\;{\beta},\;and\;{\gamma})$, Firmicutes, and Cytophaga-Flavobacterium-Bacteroid$. BAC cloning and sequencing revealed protein codings highly identical to phenylacetic acid degradation protein paaA, chromosome segregation ATPases, or cold shock protein B of present day bacteria. Throughput sequencing of the BAC clones is underway. Viable and culturable cells were recovered from the DLE sample, and characterized by their 16S rDNA sequences. Further investigation on the survivorship and functional genes from the past should help unveil the evolution of life on Earth, or elsewhere, if any.

• Preventive Nutrition and Food Science
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• 제9권1호
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• pp.7-13
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• 2004

Lactic acid fermentation of prickly pear extract (PPE) was performed by Lactobacillus rhamnosus LS, Lactobacillus bulgaricus, and Lactobacillus brevis. The PPE was pasteurized to eliminate indigenous microorganisms as well as to dissolve the partially insoluble pulp. The PPE fermented without yeast extract by L. rhamnosus LS exhibited 0.57％ acidity and 3.5${\times}$10$^{8}$ CFU/mL bacteria count. With the addition of 0.2% edible yeast extract the PPE fermented by L. rhamnosus LS exhibited 1.15％ acidity,2.7${\times}$10$^{9}$ CFU/mL bacteria count and 95.0% retention of red color. When 5％ fructose syrup was added, the PPE fermented by L. rhamnosus LS had 1.09% acidity, 6.5${\times}$10$^{8}$ CFU/mL, and 97.7% retention of red color. With 1∼3% (w/v) concentrations of starter, the PPE fermented by L. bulgaricus and L. brevis showed 0.97% and 0.65% acidities, respectively. The viable cell counts from L. rhamnosus LS fermentation were higher compared with those of other LAB. During cold storage at 4$^{\circ}C$, the viable cell count was well maintained for 3 weeks, but then rapidly decreased. The red pigment was highly stable during cold storage for 4 weeks. The pasteurized PPE fortified with 5% fructose syrup, 0.2% yeast extract, and 0.05% CaCO$_3$ was successfully fermented by inoculating with 3% LAB and incubating at 3$0^{\circ}C$ for 2 days. Both viable cell counts and the red color of the fermented PPE were well maintained during cold storage for 3 weeks.

• 미생물학회지
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• 제55권3호
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• pp.248-257
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• 2019

본 연구에서는 제주 지역의 토양 및 해양 환경으로부터 약 70주의 미생물들을 분리하였으며, 16S ribosomal RNA 유전자 분석을 통하여 최종 21종의 미생물을 발굴하였다. 이들 미생물들은 5 강(Class) 16 속(Genus)에 속하며, 모두 국내 미기록종으로 확인되었다. 분리된 미생물의 기질 특이성 및 고분자 물질 분해능을 바탕으로 내산성과 호염성 미생물들의 생리활성 표현형은 서로 구별되는 것으로 관찰되었다. 본 연구결과는, 국내 미생물 자원활용에 기초적 정보를 제공할 것으로 기대된다.

• 환경생물
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• 제41권2호
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• pp.167-178
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• 2023

Large amounts of waste and wastewater from aquaculture have negatively impacted ecosystems. Among them, shrimp aquaculture wastewater contains large amounts of nitrogen contaminants derived from feed residues in an aerobic environment. This study isolated candidate strains from adult rockworms to treat shrimp aquaculture wastewater (SAW) in an aerobic environment. Among 87 strains isolated, 25 grew well at the same temperature as the shrimp aquaculture with excellent polymer degradation ability (>0.5 cm clear zone). Six isolates (strains AL1, AL4, AL5, AL6, LA10, and PR15) were finally selected after combining strains with excellent polymer degradation ability without antagonism. 16S rRNA sequencing analysis revealed that strains AL1, AL4, AL5, AL6, LA10, and PR15 were closely related to Bacillus paramycoides, Bacillus pumilus, Stenotrophomonas rhizophila, Bacillus paranthracis, Bacillus paranthracis, and Micrococcus luteus, respectively. When these six isolates were applied to SAW, they reached a maximum cell viability of 2.06×10⁵ CFU mL^-1. Their chemical oxygen demand (COD_Cr) and total nitrogen(TN) removal rates for 12h were 51.0% and 44.6%, respectively, when the COD_Cr/TN ratio was approximately 10.0. Considering these removal rates achieved in this study under batch conditions, these six isolates could be used for aerobic denitrification. Consequently, these six isolates from rockworms are good candidates that can be applied to the field of aquaculture wastewater treatment.

• Biotechnology and Bioprocess Engineering:BBE
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• 제9권6호
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• pp.435-439
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• 2004

Three Bacillus strains were isolated from soil samples. Morphological and physiologi­cal characterization indicated that the isolated strains were B. mycoides, B. licheniformis and B. brevis. White pepper was produced from black pepper by the fermentative method using the isolates in shake flaks as well as in a large-scale fermenter. Volatile oil and piperine contents of the product were $3.2\%$ (v/w) and $4\%$ (v/w) respectively. The moisture content was $15\%$. The mi­crobial contamination was less than 10 per 100 g. The product also exhibited excellent storage stability.

• Journal of Ginseng Research
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• 제33권3호
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• pp.165-176
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• 2009

Korean ginseng, which contains ginsenosides and polysaccharides as its main constituents, is orally administered to humans. Ginsenosides and polysaccharides are not easily absorbed by the body through the intestines due to their hydrophilicity. Therefore, these constituents which include ginsenosides Rb1, Rb2, and Rc, inevitably come into contact with intestinal microflora in the alimentary tract and can be metabolized by intestinal microflora. Since most of the metabolites such as compound K and protopanaxatriol are nonpolar compared to the parental components, these metabolites are easily absorbed from the gastrointestinal tract. The absorbed metabolites may express pharmacological actions, such as antitumor, antidiabetic, anti-inflammatory, anti-allergic, and neuroprotective effects. However, the activities that metabolize these constituents to bioactive compounds differ significantly between individuals because all individuals possess characteristic indigenous strains of intestinal bacteria. Recently, ginseng has been fermented with enzymes or microbes to develop ginsengs that contain these metabolites. However, before using these enzymes and probiotics, their safety and biotransforming activity should be assessed. Intestinal microflora play an important role in the pharmacological action of orally administered ginseng.