Microbial chondroitin sulfate in experimental knee osteoarthritis model investigation of chondroprotective effect.

OBJECTIVE: Chondroitin sulfate (CS) is a glycosaminoglycan with proven anti-inflammatory, anti-apoptotic, anti-oxidant properties. CS increases type II collagen and proteoglycan synthesis in human joint chondrocytes. CS can reduce the production of pro-inflammatory mediators and proteases to improve the anabolic/catabolic balance of the extracellular cartilage matrix (ECM). Due to these characteristics, it is a natural compound that is considered to be Symptomatic Slow-Acting Drugs for Osteoarthritis (SYSADOA). Microbial chondroitin sulfate (MCS) was produced from two different bacterial sources using biotechnological methods by our team. In this study, we aimed to apply microbially produced CS and bovine-derived commercial CS forms to rabbit knees with osteoarthritis experimentally and to evaluate the results. MATERIALS AND METHODS: In this study, a cruciate ligament cutting model was applied to 40 New Zealand rabbits to induce experimental osteoarthritis. Four weeks after the surgical procedure, rabbits were divided into 4 groups as control, animal-derived MCS, E coli-derived MCS and PaJC-derived MCS group. The standard rabbit diet was fed to the control group, and the other groups were additionally fed 17 mg/kg/day CS/MCS for 12 weeks. The rabbits were sacrificed at the 12th week after surgery and the preparations obtained were evaluated histopathologically. RESULTS: As a result, it was observed that regeneration tissue was statistically significant in histopathological cartilage tissue compared to the control group of CS developed from different sources given to rabbits with osteoarthritis. It was determined that among the CS groups produced from different sources, the group with the highest chondroprotective effect was MCS originating from E.coli. CONCLUSIONS: This vegan product (MCS), which we obtained as a result of our study, was produced by our team from a microbial source. According to our analysis, it has the potential to be an effective alternative therapy agent in the treatment of osteoarthritis.

Production of L-asparaginase in Enterobacter aerogenes expressing Vitreoscilla hemoglobin for efficient oxygen uptake.

This study is the first utilizing Vitreoscilla hemoglobin in a heterologous bacterium, Enterobacter aerogenes, to determine the effect of such a highly efficient oxygen-uptake system on the production of l-asparaginase, an enzyme that has attracted considerable attention due to its anti-tumor activity. Here, we show that the Vitreoscilla hemoglobin expressing strain has from 10-fold to more than two orders of magnitude lower l-asparaginase activity than the wild type or the control without the Vitreoscilla hemoglobin gene under different aeration conditions. Aeration and agitation were also determining factors for enzyme production. The enzyme activity was reduced considerably under both full aerobic and anaerobic conditions, while the highest enzyme activity was determined in cultures under low aeration and low agitation. Also, the effect of different concentrations of glucose on enzyme production showed catabolic repression. Glucose at 1% caused almost total inhibition of enzyme activity, while at 0.1% it showed a slightly stimulatory effect on enzyme production, compared with glucose-free medium.

Effects of simulated acid rain on the pollen germination and pollen tube growth of apple (Malus sylvestris Miller cv. Golden).

The pollens of apple flowers have been treated with simulated acid rain solutions in range of pHs 2.9 to 5.0 in order to determine the threshold proportion values that lead the observed symptoms of detriments of acid rain. Compared to controls (pH 6.5), pollen germination decreased by 41.75% at pH 3.3 and pollen tube elongation decreased by 24.3% at pH 3.4. Acid rain threshold proportion value was around pH 3.3 and 3.4 for apple pollen germination and pollen tube elongation, respectively. Furthermore, pollen tube elongation was determined to be more sensitive to acid rain than pollen germination. The pH values below 3.1 resulted in complete destruction of pollen tubes. Pollen germination entirely stopped at around pH 3.0. Finally, it has been shown that the acid rain has a blocking effect on pollen germination and pollen tube elongation in apple. The conclusion is that not only pH value but also the quantity of acid rain is important factor in germination. The results were found statistically significant through the LSD test at levels of p < 0.05 and p < 0.01.

Effects of metals on seed germination, root elongation, and coleoptile and hypocotyl growth in Triticum aestivum and Cucumis sativus.

A simple, fast, and easy-to-perform method was carried out for the quantification of the inhibitory effects of metals on wheat and cucumber. The method uses seed germination, root elongation, and hypocotyl and coleoptile growth in these plants as parameters in the presence of varying concentrations of metals. Metals selected for this study were Hg, Cd, Co, Cu, Pb, and Zn. Although effective concentrations of these metals for a certain degree of inhibition were different, both plants had a reduced seed germination rate, root, and hypocotyl or coleoptile length with increasing concentrations. Mercury was determined to be the most inhibitory metal on these parameters. This metal caused a complete inhibition of germination in wheat and cucumber seeds at certain concentrations-->or=1.5 mM in cucumber and at 1.7 mM in wheat. No other metal caused this kind of inhibition even at the highest concentration (8.0 mM) applied. Though this metal possessed a higher inhibition of germination in cucumber than in wheat seeds, the inhibitory effects of other metals used were the reverse, being higher in wheat. With some exceptions, all metals in selected concentrations caused a significant ( p < 0.01 or p < 0.05) decrease in germination rate of both plants compared to control group seeds.

Cell growth and oxygen uptake of Escherichia coli and Pseudomonas aeruginosa are differently effected by the genetically engineered Vitreoscilla hemoglobin gene.

Vitreoscilla hemoglobin is a good oxygen trapping agent and its presence in genetically engineered Escherichia coli helps this bacterium to grow better. Here, the potential use of this hemoglobin, for improving the growth and the oxygen transfer properties of Pseudomonas aeruginosa as well as Escherichia coli, was investigated. To stably maintain it in both bacteria, a broad-host range cosmid vector (pHG1), containing the entire coding sequence for Vitreoscilla hemoglobin gene and its native promoter on a 2.3 kb fragment, was constructed. Though at different levels, both bacteria produced hemoglobin and while the oxygen uptake rates of vgb-bearing strains were 2-3-fold greater than that of non-vgb-bearing strains in both bacteria, the growth advantage afforded by the presence of Vitreoscilla hemoglobin was somewhat varied. As an alternative to the traditional method of the improvement of oxygen transfer properties of the environment in which cells are grown, the genetic manipulation applied here improved the oxygen utilization properties of cells themselves.