This work addresses the production of prodigiosin from ram horn peptone (RHP) using MO-1, a local isolate in submerged culture. First, a novel gram-negative and rod-shaped bacterial strain, MO-1, was isolated from the body of the grasshopper (Poecilemon tauricola Ramme 1951), which was collected from pesticide-contaminated fields. Sequence analysis of 16S rDNA classified the microbe as Serratia marcescens. The substrate utilization potential (BIOLOG) and fatty acid methyl ester profile (FAME) of S. marcescens were also determined. The effect of RHP on the production of prodigiosin by S. marcescens MO-1 was investigated, and the results showed that RHP supplementation promoted the growth of MO-1 and increased the production of prodigiosin. A concentration of 0.4% (w/v) RHP resulted in the greatest yield of prodigiosin (277.74 mg/L) after 48 h when mannitol was used as the sole source of carbon. The pigment yield was also influenced by the types of carbon sources and peptones. As a result, RHP was demonstrated to be a suitable substrate for prodigiosin production. These results revealed that prodigiosin could be produced efficiently by S. marcescens using RHP.

In the present study, production of rhamnolipid biosurfactant by Pseudomonas aeruginosa OG1 was statistically optimized by response surface methodology. Box-Behnken design was applied to determine the optimal concentrations of 52, 9.2, and 4.5 g/L for carbon source (waste frying oil), nitrogen source (chicken feather peptone), and KH 2 PO 4 , respectively, in production medium. Under the optimized cultivation conditions, rhamnolipid production reached up to 13.31 g/L (with an emulsification activity of 80%), which is approximately twofold higher than the yield obtained from preliminary cultivations. Hence, rhamnolipid production, noteworthy in the literature, was achieved with the use of statistical optimization on inexpensive waste materials for the first time in the present study.

A b s t r a c tExtensive applications of organochlorine pesticides like endosulfan have led to the contamination of soil and environments. Five different bacteria were isolated from cockroaches living in pesticide contaminated environments. According to morphological, physiological, biochemical properties, and total cellular fatty acid profile by Fatty Acid Methyl Esters (FAMEs), the isolates were identified as Pseudomonas aeruginosa G1, Stenotrophomonas maltophilia G2, Bacillus atrophaeus G3, Citrobacter amolonaticus G4 and Acinetobacter lwoffii G5. This is the first study on the bacterial flora of Blatta orientalis evaluated for the biodegradation of α-endosulfan. After 10 days of incubation, the biodegradation yields obtained from P. aeruginosa G1, S. maltophilia G2, B. atrophaeus G3, C. amolonaticus G4 and A. lwoffii G5 were 88.5% , 85.5%, 64.4%, 56.7% and 80.2%, respectively. As a result, these bacterial strains may be utilized for biodegradation of endosulfan polluted soil and environments. 64developed resistance to pesticides. If this is true, we can isolate new and effective α-endosulfan degrading bacteria from cockroaches' microflora and these isolates can be used for the biological treatment of waters and soils polluted with endosulfan and other insecticides. Experimental Material and MethodsChemicals. α-endosulfan and reagents were purchased from Sigma-Aldrich (St Louis, MO, USA). All solvents used were of the highest analytical grade and were employed without further purification. The stock α-endosulfan solution was prepared in acetone and used for all the experiments. The chemical structure and the most important physical parameters of endosulfan are summarized in Fig. 1 O, 24 (Siddique et al., 2003). After 7 days, 5 ml of each culture was re-inoculated into new α-endosulfan-NSM medium and further incubated at 30°C for 7 days. This subculture was repeated under the same culture conditions, and then an aliquot (0.2 ml) from each culture was applied to solid α-endosulfan-NSM for isolation of single colonies.Identification of endosulfan degrading microorganisms. α-endosulfan degrading bacterial isolates were identified by various tests, such as pigment formation, Gram staining, nitrate reduction, catalase and oxidase tests, and starch hydrolysis. Biochemical reactions were conducted according to Benson (2001). Biochemical activities were determined according to the recommended scheme of Bergey's Manual of Determinative Bacteriology (Holt et al., 1994). Identification was confirmed by the fatty acid analysis for all bacterial isolates. Fatty acid methyl ester (FAME) profiles of each bacterial strain were identified by comparing the commercial databases (Tripticase Soy Broth Agar 40) with the MIS software package. The identity of bacterial strains was revealed by computer comparison of FAME profiles of the unknown test strains with those in the library. FAMEs were separated by gas chromatography (HP6890, Hewlett Packard, Palo Alto, CA, USA) with a fused-silica capillary column (25 m × 0.2 mm) with cr...

Indole acetic acid (IAA) is a plant growth-promoting hormone used in agriculture; therefore, its continuous production is of paramount importance. IAA-producing eight bacteria were isolated from the rhizosphere of Verbascum vulcanicum. Among them, Arthrobacter agilis A17 gave maximum IAA production (75 mg/L) and this strain was used to immobilization studies. The A. agilis A17 cells were immobilized in calcium alginate for the production of IAA. Optimization of process parameters for IAA production was carried out to enhance IAA production using immobilized cells. The maximal production of IAA was 520 mg/L under the following optimal conditions: 1% mannitol, 30 °C, pH 8.0, and 24 h incubation. It was determined that the immobilized cells could be reused (13 times) for the production of IAA.

Stenotrophomonas maltophilia OG2 was isolated from the intestine of cockroaches that was collected from a cow barn contaminated some pesticides belong to pyrethroid and organochlorine groups. OG2 was able to degrade a-endosulfan in non sulfur medium (NSM) as a sole sulfur source for growth within 10 days of incubation. The effects of some growth parameters on endosulfan biodegradation by OG2 was studied and found that the biodegradation was significantly affected by the endosulfan concentrations, pH and temperature. Experimental results obtained in different conditions show that the optimum concentration of a-endosulfan, pH and temperature were 100 mg/L, 8.0 and 30°C, respectively. Under these conditions, the bacterium degraded 81.53% of the a-endosulfan after 10 days. The concentration of a-endosulfan and its metabolites was determined by HPLC. Endosulfan ether, endosulfan lactone and endosulfan diol were the main metabolites in culture, but did not produce toxic metabolite, endosulfan sulfate. These results suggested that S. maltophilia OG2 degrades a-endosulfan via a hydrolysis pathway. The present study indicates that strain OG2 may have potential use in the biodegradation of pesticides contaminated environments.