Polymeric and Compositional Properties of Novel Extracellular Microbial Polyglucosamine Biopolymer from New Strain of Citrobacter sp. BL-4

Abstract

A novel polyglucosamine polymer, PGB-2, was produced extracellularly from a new strain Citrobacter sp. BL-4 using pH-stat fed batch cultivation. It was composed of 97.3% glucosamine and 2.7% rhamnose; its average molecular weight, solubility in 2% acetic acid and viscosity were 20 kDa, 5 g l(-1) and 2.9 cps, respectively. FT-IR and 1H NMR spectra of PGB-2 revealed a close identity with chitosan from crab shells.

Bioflocculants from isolated strain or mixed culture: Role of phosphate salts and Ca2+ ions

“…The extracellular polymeric substances (EPS) excreted by microorganisms in activated sludge or aerobic granules can have high flocculating capability to particles or cells. Based on this understanding, the biopolymers collected from fermentation broth were assumed the bioflocculants of interest and were subsequently analyzed [7,[24][25][26][27][28][29]. Daolun et al [16] claimed that the presence of Al 3+ , Mg 2+ , Ca 2+ , K + and Na + enhanced flocculating efficiency.…”

“…With added phosphate salt and the co-ions, the high flocculating efficiency of the reported studies had a possibility to be yielded by the flocculating capability of phosphate and the coions such as Ca 2+ . (In the references studied only Kim et al [27] presented the only study on EPS production by Citrobacter sp. with no addition of phosphate salts; however, these authors did not test the flocculating activities of the yielded EPS so no comparison can be made herein.…”

Production and characterization of a thermostable bioflocculant from Bacillus subtilis F9, isolated from wastewater sludge

“…The genomic DNA was isolated and subjected to amplification of 16S rDNA using universal primers. The amplified product was gel purified using a QIAGEN gel extraction kit (QIA-GEN Inc., USA) and the purified products were sequenced as previously described by Kim et al (2006). The 16S rDNA sequence ( $1089 bp) was compared with 16S rDNA sequences that are currently available in the NCBI GenBank database.…”

Characterization of bioflocculants produced by bacteria isolated from crude petroleum oil

“…Their isolated genomic DNA was subjected to PCR amplification of 16 S rDNA using universal primers. Amplified products were gel purified using Qiagen gel extraction kit and purified products were sequenced (Kim et al, 2006). Subsequently, comparative sequence analysis of 16 S rDNA amplified genes was performed and a phylogenetic tree was generated according to the procedure described previously by Al-Thani et al (2009).…”