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.

Abstract. Four different strains of Bacillus cereus producing indole-3-acetic acid (IAA) were isolated from various rhizospheric soils and characterized biochemically. The isolates were screened for (IAA) production and BC-On strain was found to be the best IAA producer with 46.25 mg/l. Maximum IAA production was obtained in the stationary growth phase at 72h. Significant correlation was also observed between IAA production and growth of the B. cereus strains. Among the isolates, BC-On strain was further used for immobilization studies. Maximum IAA production was obtained at initial pH of 8.0 and temperature of 35 °C after 18 h of fermentation. The immobilized cells could be effectively reused thirteen times and the IAA concentration of 300 mg/l was determined during this period. Results showed that immobilized cells can be used in the continuous process for the production of IAA. The productivity obtained by immobilization was higher than the one obtained by submerged cultivation and immobilization reduced the fermentation time.Keywords: Indole-3-acetic acid, Rhizobacteria, Bacillus cereus, Immobilization Immobilize Bacillus cereus Hücreleri Tarafından İndol-3-Asetik Asitin BiyosenteziÖzet. İndol-3-asetik asit (İAA) üreten dört farklı Bacillus cereus straini çeşitli rizosfer topraklarından izole edildi ve biyokimyasal olarak karakterize edilmiştir. İzolatlar İAA üretimi için taranmış ve BC-On straini 46.25 mg/l ile en iyi İAA üreticisi olarak bulunmuştur. En fazla IAA üretimi 72. saatte durağan büyüme fazında elde edilmiştir. B. cereus strainlerinin IAA üretimi ve büyüme arasında önemli bir ilişki gözlenmiştir. İzolatlar arasında, BC-On straini immobilizasyon çalışmalarında kullanılmıştır. En fazla IAA üretimi 18 saatlik fermentasyon sonrasında başlangıç pH'sı 8.0 ve 35 °C elde edilmiştir. İmmobilize edilmiş hücreler etkili olarak on üç kez kullanılabilmiş ve bu süre boyunca 300 mg/l İAA konsantrasyonu tespit edilmiştir. Sonuçlar immobilize hücrelerin IAA üretimi için sürekli bir işlemde kullanılabilir olduğunu göstermiştir. İmmobilizasyon ile elde edilen verimlilik, derin fermentasyon ile elde edilenden daha yüksek olduğu bulunmuş ve immobilizasyon fermentasyon süresini kısaltmıştır.

Four linear nonphenolic diarylheptanoids were synthesized and their antibacterial activities were studied. (S)-2-Me-CBS-catalysed reduction of alnustone with BH 3 .SMe 2 gave (R) (-)(4 E ,6 E)-1,7-diphenylhepta-4,6-dien-3-ol, a natural product. Reduction of alnustone with Na in t-BuOH at-15°C under NH 3 atm gave (E)-1,7-diphenylhept-5en-3-one as a Birch-type reduction product. t-BuOK catalysed condensation of benzalacetone with propionyl chloride gave (4 Z ,6 E)-5-hydroxy-1,7-diphenylhepta-4,6-dien-3-one, a natural product. (1 E ,4 Z ,6 E)-5-Hydroxy-4-phenethyl-1,7-diphenylhepta-1,4,6-trien-3-one, a curcuminoid, was synthesized starting from pentan-2,4-dione in 3 steps. The synthesized chemical compounds were applied against 2 gram-positive bacteria (Bacillus cereus and Arthrobacter agilis), 4 gram-negative bacteria (Pseudomonas aeruginosa, Xanthomonas campestris, Klebsiella oxytoca, and Helicobacter pylori), and 1 yeast (Candida albicans) by the disc diffusion method. All of the synthesized compound exhibited different degrees of antimicrobial activity at concentrations between 20-100 µg/disc against the test organisms.

Increasing of industrialization and population has resulted in the accumulation of a wide variety of chemicals. Especially, widespread use of synthetic and toxic chemicals have led to an effort to improve new technologies to reduce or eliminate these contaminants from the environment. Chemical methods that used for the treatment of toxic materials are expensive, time-consuming and difficult, especially in extensive agricultural areas. Furthermore these methods led to formation of new chemical pollutants. Recent years, one promising alternative treatment method is to use of microorganisms for the biodegradation of these toxic chemicals. This method is effective, minimally hazardous, economical, versatile and environment friendly. In this study, we thought that microflora of insecticide resistant insects may be a potential reservoir for the isolation of new bacteria that can be used for the biodegradation of insecticides. In this research work, totally 24 bacterial isolates capable of biodegradation α-endosulsan were isolated from the body microflora of insects belong to Orthoptera, Dermaptera, Mantodea and Hymenoptera orders. Based on the some morphological, physiological and biochemical characteristics and fatty acid profiles they were identified as Stenotrophomonas, Pseudomonas, Acinetobacter, Bacillus, Brevibacillus, Flavimonas and Rhodococcus. As a result, these isolates can be used for the treatment of α-endosulfan residues at different environments.