Aims: Attention to ice nucleation proteins has increased for more than two decades. Ice nucleation proteins have been utilized for artificial snow-making known as Snowmax™, cryopreservation of tissues and cells, and cloud condensation nuclei. There is a direct relationship between bacterial growth and ice nucleation activity. Therefore, the optimization of the culture medium seems necessary. Methodology and results: The effect of different carbon and nitrogen sources on the growth of a new native Pseudomonas sp. IRL.INP1 was evaluated by using fractional factorial design, the path of the steepest ascent experiment and central composite design. Ice nucleation activity, biomass and whole-cell protein were identified afterward. The model predicted by response surface methodology indicated that the maximum bacterial growth was observed when sucrose, ammonium sulfate [(NH4)2SO4] and manganese (II) (Mn2+) were utilized at 12.46 g/L, 321.97 mg/L and 938.09 µM, respectively. Also, 1.10 g/L biomass and 0.85 µg/µL whole-cell proteins were gained, and the isolate showed ice nucleation activity 31 sec sooner after optimization. Conclusion, significance and impact of study Ice nucleation proteins are growth-dependent and the growth condition optimization leads to higher bacterial cells growth. Therefore, best bacterial growth was obtained when proper carbon and nitrogen sources were used, and ice nucleation activity was observed in shorter time. This is the first study concerning ice nucleation activity optimization using different carbon and nitrogen sources.
Gram-Negative Bacteria--growth & ; development ; Pseudomonas

OBJECTIVEBioremediation technology has gained importance because microbes could be the convenient source of bio-absorption/bioaccumulation of metals from effluent streams.

METHODSThe nickel-resistant bacterial isolates (NiRBI) were selected from various bacterial isolates from industrial effluent and grown in nutrient broth containing different concentrations of nickel sulfate (0.3-3.0 mmol/L) and their capability of accumulating metal from the medium.

RESULTSWell-defined growth of NiRBI was observed in the medium containing up to 2.5 mmol/L of nickel. The isolate was identified using 16S rRNA and closely related to Pseudomonas fragi. Maximum accumulation of nickel (0.59 mg/g dry weight of bacterial cells) was observed when NiRBI was grown in media containing 2 mmol/L of nickel. The protein profile of the NiRBI cellular extract by SDS-PAGE showed two metal stress-induced proteins of molecular weight 48 KD and 18 KD with a simultaneous down regulation of four proteins of 46.7 KD, 42.2 KD, 19.7 KD, and 4.0 KD.

CONCLUSION48 KD and 18 KD proteins play a role in metal resistance mechanism by NiRBI.

Biodegradation, Environmental ; Electrophoresis, Polyacrylamide Gel ; Gram-Negative Bacteria ; genetics ; growth & development ; metabolism ; Kinetics ; Nickel ; metabolism ; Phylogeny ; RNA, Ribosomal, 16S ; classification ; genetics

OBJECTIVEIn order to use facultative gut bacteria as an alternate to animals for the initial gastrointestinal toxicity screening of heavy metals, a comparative study on rat intestinal epithelial cells and resident gut bacteria was undertaken.

METHODSin vitro growth rate of four gut bacteria, dehydrogenase (DHA) and esterase (EA) activity test, intestinal epithelial and bacterial cell membrane enzymes and in situ effect of arsenite were analysed.

RESULTSGrowth profile of mixed resident population of gut bacteria and pure isolates of Escherichia coli, Pseudomonas sp., Lactobacillus sp., and Staphylococcus sp. revealed an arsenite (2-20 ppm) concentration-dependent inhibition. The viability pattern of epithelial cells also showed similar changes. DHA and EA tests revealed significant inhibition (40%-72%) with arsenite exposure of 5 and 10 ppm in isolated gut bacteria and epithelial cells. Decrease in membrane alkaline phosphatase and Ca2+ -Mg2+ -ATPase activities was in the range of 33%-55% in four bacteria at the arsenite exposure of 10 ppm, whereas it was 60%-65% in intestinal epithelial villus cells. in situ incubation of arsenite using intestinal loops also showed more or less similar changes in membrane enzymes of resident gut bacterial population and epithelial cells.

CONCLUSIONThe results indicate that facultative gut bacteria can be used as suitable in vitro model for the preliminary screening of arsenical gastrointestinal cytotoxic effects.

Animals ; Arsenites ; pharmacology ; Cell Membrane ; drug effects ; Culture Media ; Epithelial Cells ; drug effects ; enzymology ; microbiology ; Esterases ; metabolism ; Gram-Negative Bacteria ; drug effects ; enzymology ; growth & development ; Gram-Positive Bacteria ; drug effects ; enzymology ; growth & development ; Humans ; Intestines ; cytology ; drug effects ; microbiology ; Oxidoreductases ; metabolism ; Rats ; Teratogens ; pharmacology

PURPOSE: Lipopolysaccharide (LPS) is a cell wall component of Gram-negative bacteria and important for pro-inflammatory mediators. This study aimed to establish a rhinitis model using ovalbumin (OVA) and LPS in order to evaluate the role of interleukin (IL)-17 in the pathogenesis of an LPS-induced non-eosionophilic rhinitis model. METHODS: Mice were divided into 4 groups and each group consisted of 10 mice (negative control group, allergic rhinitis model group, 1-µg LPS treatment group, and 10-µg LPS treatment group). BALB/c mice were sensitized with OVA and 1 or 10 µg of LPS, and challenged intranasally with OVA. Multiple parameters of rhinitis were also evaluated to establish the LPS-induced rhinitis model. IL-17 knockout mice were used to check if the LPS-induced rhinitis model were dependent on IL-17. Eosinophil and neutrophil infiltration, and mRNA and protein expression profiles of cytokine in nasal mucosa or spleen cell culture were evaluated using molecular, biochemical, histopathological, and immunohistological methods. RESULTS: In the LPS-induced rhinitis model, neutrophil infiltration increased in the nasal mucosa, and systemic and nasal IL-17 and interferon-gamma (IFN-γ) levels also increased as compared with the OVA-induced allergic rhinitis model. These findings were LPS-dose-dependent. In IL-17 knockout mice, those phenotypes (neutrophil infiltration, IL-17, and IFN-γ) were reversed, showing IL-17 dependency of LPS-induced rhinitis. The expression of vascular endothelial growth factor (VEGF), an important mediator for inflammation and angiogenesis, decreased in IL-17 knockout mice, showing the relationship between IL-17 and VEGF. CONCLUSIONS: This study established an LPS-induced rhinitis model dependent on IL-17, characterized by neutrophil infiltration and increased expression of IL-17.
Animals ; Cell Culture Techniques ; Cell Wall ; Eosinophils ; Gram-Negative Bacteria ; Inflammation ; Interferon-gamma ; Interleukin-17* ; Interleukins ; Mice ; Mice, Knockout ; Nasal Mucosa ; Neutrophil Infiltration ; Ovalbumin ; Ovum ; Phenotype ; Rhinitis* ; Rhinitis, Allergic ; RNA, Messenger ; Spleen ; Vascular Endothelial Growth Factor A

Inflammation is one of the most prominent characteristic features of chronic liver disease, liver fibrosis, cirrhosis, and hepatocellular carcinoma (HCC). Most of HCC cases develop in patients with cirrhosis and cirrhosis develops in patients with chronic liver inflammation. Therefore, there is no doubt that there exist some strong connection among inflammation, fibrosis, and cancer. In fact, chronic unresolved inflammation is associated with persistent hepatic injury and concurrent regeneration, leading to sequential development of fibrosis, cirrhosis, and eventually HCC. This review will discuss the common mechanism of inflammation and fibrosis in chronic liver diseases, and then demonstrate why HCC develops in inflammatory and fibrotic conditions.
Carcinoma, Hepatocellular/*etiology ; Gram-Negative Bacteria/growth & development ; Hepatitis, Chronic/*complications/metabolism/microbiology ; Humans ; Hypoxia ; *Inflammation ; Lipopolysaccharides/metabolism ; Liver/metabolism/pathology ; Liver Cirrhosis/*complications ; Liver Neoplasms/*etiology ; Toll-Like Receptors/metabolism

Porcine proliferative enteropathy(PPE) is an enteric disease been caused by Lawsonia intracellularis. It has become one of the critical problems in the pig industry. To investigate the prevalence of PPE in Korea, serum samples of 828 pigs from 65 herds were tested using indirect immunofluorescence antibody technique(IFA). The infection rate in individual pigs varied from 44 to 69%, whereas 100% in pig farms. The infection frequency was 57, 44.9, and 59.4% according to age respectively. Administration of tylosin in feed at a concentration of 110 ppm for 14 days reduced the infection rate of the farms. These data indicated that the high prevalence of PPE may be controlled by tylosin.
Administration, Oral ; Animal Feed ; Animals ; Anti-Bacterial Agents/*therapeutic use ; Antibodies, Bacterial/blood ; Enteritis/epidemiology/prevention&control/*veterinary ; Fluorescent Antibody Technique, Indirect/veterinary ; Gram-Negative Bacterial Infections/prevention&control/*veterinary ; Korea/epidemiology ; *Lawsonia Bacteria/drug effects/growth&development/immunology ; Seroepidemiologic Studies ; Swine ; Swine Diseases/*epidemiology/microbiology/prevention&control ; Tylosin/*therapeutic use