Journal of Microbiology

Research Support, Non-U.S. Gov'ts

Lactobacillus paracasei subsp. paracasei LC01 Positively Modulates Intestinal Microflora in Healthy Young Adults: Hao Zhang , Jing Sun , Xianting Liu , Chuan Hong , Yuanbo Zhu , Aiping Liu , Siqi Li , Huiyuan Guo , Fazheng Ren; J. Microbiol. 2013;51(6):777-782. Published online December 19, 2013; DOI: https://doi.org/10.1007/s12275-013-3279-2

14 View
0 Download
29 Citations

Abstract: Lactobacillus paracasei subsp. paracasei LC01 (LC01) can tolerate intestinal stresses and has antioxidant activity. To evaluate the effect of the bacterium on human intestinal microflora, a randomized, double-blind, placebo-controlled human trial was carried out. Fifty-two healthy adult volunteers were randomized equally to two groups. One group consumed 12% (wt/vol) skimmed milk supplemented with 1010 CFU of LC01 each day for the 4-week treatment period, and then consumed placebo in the next treatment period, separated by a 2-week washout. The other group followed the reverse order. Group-specific real-time PCR and biochemical analyses was used to determine the intestinal bacterial composition of fecal samples collected at the end of every period, and the concentration of short-chain fatty acids and ammonia. A significant inhibition in fecal Escherichia coli and increase in Lactobacillus, Bifidobacterium, and Roseburia intestinalis were observed after consumption of LC01. Acetic acid and butyric acid were significantly higher in the probiotic stage and fecal ammonia was significantly lower. The results indicated a modulation effect of LC01 on the intestinal microflora of young adults, suggesting a beneficial effect on bowel health. LC01 may have potential value as a probiotic.

Phenotypic and Phylogenetic Analysis of Lactic Acid Bacteria Isolated from Forage Crops and Grasses in the Tibetan Plateau: Huili Pang , Zhongfang Tan , Guangyong Qin , Yanping Wang , Zongwei Li , Qingsheng Jin , Yimin Cai; J. Microbiol. 2012;50(1):63-71. Published online February 27, 2012; DOI: https://doi.org/10.1007/s12275-012-1284-5

12 View
0 Download
53 Citations

Abstract: A total of 140 lactic acid bacteria (LAB) strains were isolated from corn, alfalfa, clover, sainfoin, and Indian goosegrass in the Tibetan Plateau. According to phenotypic and chemotaxonomic characteristics, 16S rDNA sequence, and recA gene PCR amplification, these LAB isolates were identified as belonging to five genera and nine species. Corn contained more LAB species than other forage crops. Leuconostoc pseudomesenteroides, Lactococcus lactis subsp. lactis, Lactobacillus brevis, and Weissella paramesenteroides were dominant members of the LAB population on alfalfa, clover, sainfoin, and Indian goosegrass, respectively. The comprehensive 16S rDNA and recA-based approach effectively described the LAB community structure of the relatively abundant LAB species distributed on different forage crops. This is the first report describing the diversity and natural populations of LAB associated with Tibetan forage crops, and most isolates grow well at or below 10°C. The results will be valuable for the future design of appropriate inoculants for silage fermentation in this very cold area.

Microflora Profiling of Infected Root Canal before and after Treatment Using Culture-Independent Methods: Yasuhiro Ito , Takuichi Sato , Keiko Yamaki , Gen Mayanagi , Kazuhiro Hashimoto , Hidetoshi Shimauchi , Nobuhiro Takahashi; J. Microbiol. 2012;50(1):58-62. Published online February 27, 2012; DOI: https://doi.org/10.1007/s12275-012-0459-4

14 View
0 Download
11 Citations

Abstract: This study aimed to profile the microflora in infected root canals before and after root canal treatment using cultureindependent
methods
. Six infected root canals in singlerooted teeth with periapical lesions from five subjects were included. Quantification of total bacteria was performed by real-time PCR with primers targeting 16S rRNA genes. PCR products with universal 16S rRNA gene primers were cloned and partially sequenced, and bacterial identification at the species level was performed by comparative analysis with the GenBank database. The concentration of extracted DNA before treatment was higher than that after root canal treatment, although the difference was not statistically significant. Sequence analysis revealed that oral bacteria such as Fusobacterium, Streptococcus, Olsenella, and Pseudoramibacter detected in cases before root canal treatment disappeared after treatment. These results suggest that the root canal microflora are distinct before and after root canal treatment, and that treatment changes the microflora in both quantity and quality.

Lactobacillus salivarius REN Counteracted Unfavorable 4-Nitroquinoline-1-Oxide-Induced Changes in Colonic Microflora of Rats: Ming Zhang , Xuewei Qiao , Liang Zhao , Lu Jiang , Fazheng Ren; J. Microbiol. 2011;49(6):877-883. Published online December 28, 2011; DOI: https://doi.org/10.1007/s12275-011-1137-7

12 View
0 Download
14 Citations

Abstract: Probiotics and carcinogens both have a significant effect on the microfloral composition of the human intestine. The objective of this study was to investigate the impact of an important carcinogen, 4-Nitroquinoline-1- Oxide on colonic microflora and the efficacy of the probiotic Lactobacillus salivarius REN as an agent of counteracting these effects. Using denaturing gradient gel electrophoresis (DGGE) combined with redundancy analysis, we demonstrated that both 4-Nitroquinoline-1-Oxide and L. salivarius REN significantly altered the bacterial communities of rat colons. A total of 27 bacterial strains were identified as being affected by treatment with 4-Nitroquinoline-1-Oxide or L. salivarius REN using a t-value biplot combined with band sequencing. 4-Nitroquinoline-1-Oxide treatment increased the abundance of two potential pathogens (one Helicobacter strain and one Desulfovibrio strain), as well as reducing the abundance of two potentially beneficial strains (one Ruminococcaceae strain and one Rumen bacteria). The Helicobacter strain was initally detected in carcinogen-treated rat intestinal microflora, but L. salivarius REN treatment effectively suppressed the growth of the Helicobacter strain. These results suggested that L. salivarius REN may be a potential probiotic, efficiently acting against the initial infection with, and the growth of pathogenic bacteria.

Correlations of Fecal Bacterial Communities with Age and Living Region for the Elderly Living in Bama, Guangxi, China: Liang Zhao , Xuewei Qiao , Jun Zhu , Xiaoying Zhang , Jingli Jiang , Yanling Hao , Fazheng Ren; J. Microbiol. 2011;49(2):186-192. Published online May 3, 2011; DOI: https://doi.org/10.1007/s12275-011-0405-x

14 View
0 Download
22 Citations

Abstract: Bama County (Guangxi, China) is famous for its longevous population. In this study, intestinal microflora of 17 healthy elderly subjects of different ages and from different regions (rural and urban) in Bama, were analyzed by denaturing gradient gel electrophoresis (DGGE). Significant effects of age and living region on the whole intestinal bacterial communities were observed by redundancy analysis (RDA). A total of 11 bacterial strains that were correlated with age and living region were identified using a t-value biplot combined with band sequencing. Four bacterial strains were correlated with both age and living region of the elderly in Bama. Two Bacteroides strains and one Ruminococcaceae strain were abundant in the rural, younger elderly; conversely, one Desulfovibrio strain was high in the urban, older elderly. Another Bacteroidetes strain was only correlated with the participant’s age, and its abundance increased with the age of the elderly. The richness of one Clostridium sordellii strain, which was only correlated with the elderly living region, was high in the urban elderly. The study also found five other novel bacterial strains that were correlated with the age or living region of the elderly in Bama. These results expand our understanding of age- and region-effects on the intestinal microflora of the elderly and raise the possibility of developing probiotics originating from centenarians.

Screening and Characterization of a Cellulase Gene from the Gut Microflora of Abalone Using Metagenomic Library: Duwoon Kim , Se-Na Kim , Keun Sik Baik , Seong Chan Park , Chae Hong Lim , Jong-Oh Kim , Tai-Sun Shin , Myung-Joo Oh , Chi Nam Seong; J. Microbiol. 2011;49(1):141-145. Published online March 3, 2011; DOI: https://doi.org/10.1007/s12275-011-0205-3

6 View
0 Download
15 Citations

Abstract: A metagenomic fosmid library was constructed using genomic DNA isolated from abalone intestine. Screening of a library of 3,840 clones revealed a 36 kb insert of a cellulase positive clone (pAM11E10). A shotgun clone library was constructed using the positive clone (pAM11E10) and further screening of 3,840 shotgun clones with an approximately 5 kb insert size using a Congo red overlay revealed only one cellulase positive clone (pAM11L9). The pAM11L9 consisted of a 5,293-bp DNA sequence and three open reading frames (ORFs). Among the three ORFs, cellulase activity was only shown in the recombinant protein (CelAM11) coded by ORF3, which showed 100% identity with outer membrane protein A from Vibrio alginolyticus 12G01, but no significant sequence homology to known cellulases. The expressed protein (CelAM11) has a molecular weight of approximately 37 kDa and the highest CMC hydrolysis activity was observed at pH 7.0 and 37°C. The carboxymethyl cellulase activity was determined by zymogram active staining and different degraded product profiles for CelAM11 were obtained when cellotetraose and cellopentaose were used as the substrates, while no substrate hydrolysis was observed on oligosaccharides such as cellobiose and cellotriose.

Pseudoxanthomonas icgebensis sp. nov., Isolated from the Midgut of Anopheles stephensi Field-Collected Larvae§: Asha Rani , Anil Sharma , Tridibes Adak , Raj K. Bhatnagar; J. Microbiol. 2010;48(5):601-606. Published online November 3, 2010; DOI: https://doi.org/10.1007/s12275-010-0125-7

11 View
0 Download
4 Citations

Abstract: A Gram-negative, aerobic, golden yellow, rod-shaped bacterium, a strain designated ICGEB-L15T, was isolated from the larval midgut of Anopheles stephensi captured in District Jhajjar, Haryana, India. The strain ICGEB-L15T grows at 30-50°C (optimum 30-37°C), pH 6.5-8.5 (optimum 7.0-8.0) and in the presence of 2% NaCl. The major fatty acids were iso-C15:0 (22.5% of total fatty acid), anteiso-C15:0 (16.5%), iso-C17:1ω9c (10.3%), iso-C16:0 (7.3%), C16:0 (6.1%), and iso-C11:0 (5.3%). The strain showed the highest 16S rRNA gene sequence similarities with the type strains Pseudoxanthomonas daejeonensis KCTC 12207T (97.4%), Pseudoxanthomonas kaohsiungensis J36T (97.17%), and Pseudoxanthomonas mexicana AMX 26BT (97.11%). The DNA relatedness between ICGEB-L15T and Pseudoxanthomonas daejeonensis KCTC 12207T, Pseudoxanthomonas kaohsiungensis J36T and Pseudoxanthomonas mexicana AMX 26BT was 24.5%, 28.2%, and 33.6%, respectively. The G+C content of genomic DNA was 69.9 mol%. The major isoprenoid quinone of strain ICGEB-L15T was Q-8. The strain ICGEB-L15T represents a novel species of the genus Pseudoxanthomonas based on physiological, biochemical and phylogenetic properties; therefore, the name Pseudoxanthomonas icgebensis sp. nov. is proposed. The type strain is ICGEB-L15T (=KACC 14090T =DSM 22536T).

Identification of intestinal microflora in rainbow trout: Lee, Soon Deuk , Lee, Yeon Hee; J. Microbiol. 1995;33(4):273-277.

14 View
0 Download

Abstract: Although trout farming is well established in Korea, very little information is available on the composition of intestinal microflora in rainbow trout (Salmo gairdnerii). In 1994, from October through November, we investigated the composition and succession of intestinal bacteria. As fish grew, total viable counts increased dramatically until 45 days after fertilization when anaerobes started to appear on the media. After this time, they increased steadily. Ten aerobic generic were identified and Gram negative bacteria constituted 85% of total isolates. Among these, Pseudomonas, Eikenella, and Alcaligenes were the three major genera. Six anaerobic genera were isolated and identified. The ratio of anaerobes to aerobes was about 1 : 1 in adult trout and the composition of genera was changed under different conditions.

First
Prev
Page of 1
Next
Last

Search