Journal of Microbiology

Journal Article

PROTOCOL] Applications of different solvents and conditions for differential extraction of lipopolysaccharide in Gram-negative bacteria: Mai Phuong Nguyen , Le Viet Ha Tran , Hyun Namgoong , Yong-Hak Kim; J. Microbiol. 2019;57(8):644-654. Published online May 23, 2019; DOI: https://doi.org/10.1007/s12275-019-9116-5

Abstract: Lipopolysaccharide (LPS) is one of the major components in the outer membrane of Gram-negative bacteria. However, its heterogeneity and variability in different bacteria and differentiation conditions make it difficult to extract all of the structural variants. We designed a solution to improve quality and biological activity of LPS extracted from various bacteria with different types of LPS, as compared to conventional
methods
. We introduced a quality index as a simple measure of LPS purity in terms of a degree of polysaccharide content detected by absorbance at 204 nm. Further experiments using gel electrophoresis, endotoxin test, and macrophage activation test were performed to evaluate the performance and reliability of a proposed ‘T-sol’ method and the biological effectiveness and character of the LPS products. We presented that the T-sol method had differential effects on extraction of a RAW 264.7 cell-activating LPS, which was effective in the macrophage activation with similar effects in stimulating the production of TNF-alpha. In conclusion, the T-sol method provides a simple way to improve quality and biological activity of LPS with high yield.

Research Support, Non-U.S. Gov't

NOTE] Pontibacter jeungdoensis sp. nov., Isolated from a Solar Saltern in Korea: Yochan Joung , Haneul Kim , Beom-Il Lee , Heeyoung Kang , Tae Yong Jang , O-Seob Kwon , Kiseong Joh; J. Microbiol. 2013;51(4):531-535. Published online August 30, 2013; DOI: https://doi.org/10.1007/s12275-013-2324-5

Abstract: A Gram-staining-negative, rod-shaped and red-pigmented bacterial strain, HMD3125T, was isolated from a solar saltern in Jeungdo, Republic of Korea. A phylogenetic tree based on 16S rRNA gene sequences showed that strain HMD3125T formed a lineage within the genus Pontibacter and was similar to Pontibacter salisaro (96.1%) and P. korlensis (95.3%). The major fatty acids of strain HMD3125T were summed feature 4 (comprising iso-C17:1 I and/or anteiso-C17:1 B; 30.4%), iso-C15:0 (20.4%) and iso-C17:0 3OH (17.2%). The polar lipid profile of HMD3125T consisted of the phosphatidylethanolamine, four unidentified polar lipids, unidentified phospholipid, unidentified aminolipid and unidentified aminophospholipid. Strain HMD3125T contained MK-7 as the predominant menaquinone and sym-homospermidine as the major polyamine. The DNA G+C content of strain HMD3125T was 45.6 mol%. Strain HMD3125T assigned as a novel species in the genus Pontibacter, for which the name Pontibacter jeungdoensis sp. nov. is proposed. The type strain is HMD3125T (=KCTC 23156T =CECT 7710T).

Journal Article

Optimization of Lactic Acid Production in SSF by Lactobacillus amylovorus NRRL B-4542 Using Taguchi Methodology: Pyde Acharya Nagarjun , Ravella Sreenivas Rao , Swargam Rajesham , Linga Venkateswar Rao; J. Microbiol. 2005;43(1):38-43.; DOI: https://doi.org/2140 [pii]

Abstract: Lactic acid production parameter optimization using Lactobacillus amylovorus NRRL B-4542 was performed using the design of experiments (DOE) available in the form of an orthogonal array and a software for automatic design and analysis of the experiments, both based on Taguchi protocol. Optimal levels of physical parameters and key media components namely temperature, pH, inoculum size, moisture, yeast extract, MgSO_4 . 7H_20, Tween 80, and corn steep liquor (CSL) were determined. Among the physical parameters, temperature contributed higher influence, and among media components, yeast extract, MgSO_4 . 7H_20, and Tween 80 played important roles in the conversion of starch to lactic acid. The expected yield of lactic acid under these optimal conditions was 95.80% and the actual yield at optimum conditions was 93.50%.

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