Esabi Basaran Kurbanoglu

Asymmetric reduction of substituted acetophenones using once immobilized Rhodotorula glutinis cells

The asymmetric reductions of acetophenone and its analogues using once immobilized Rhodotorula glutinis cells were studied. The performance and reaction parameters of the immobilized cells were also investigated and it was determined that the cells could be used 15 times in batch processes. All chiral alcohols obtained using purification procedures were of sufficient enantiopurity (>99%) of the (S)-enantiomer. The applicability of the optimized process for a preparative scale bioreduction was shown. Under the optimum conditions, 35mM (4.3g) of the product ((S)-1-phenylethanol) was produced from 45mM (5.4g) of the substrate (acetophenone) with one time immobilized R. glutinis EBK-2 cells (6g wet weight). The yield was calculated as 77%. In this study, it was found that the buffer level had a very significant effect on the reaction activity. Our results demonstrate that the optimized process can be implemented on a preparative scale.

A New Process for the Utilization as Peptone of Ram Horn Waste

A peptone for utilization in microbiological culture media can be produced from rams horns. A major component of the horns is protein. Peptones are defined as protein hydrolysates. Ram horns obtained from a slaughterhouse in Erzurum, Turkey were hydrolyzed by treatment with acid (6N-HCl) and ram horn hydrolysate (RHH) was obtained. The RHH was evaporated and termed ram horn peptone (RHP). RHP was compared with a bacto-tryptone from casein and other peptones. The results show that RHP can be utilized as a peptone and may be a valuable supplement in biotechnology.

Single-cell protein production from ram horn hydrolysate by bacteria

Ram horns obtained from the slaughterhouse of Erzurum, Turkey were hydrolyzed by treating with acid (6N-HCl) and ram horn hydrolysate (RHH) was obtained. The hydrolysate was used as substrate to grow Bacillus cereus NRRL B-3711, Bacillus subtilis NRRL NRS-744 and Escherichia coli in batch system at 30 degrees C; air 1.5 v/v/min; stirring 150 rpm. Both RHH and biomass samples were analyzed. The bacterial cells produced in this hydrolysate were found to be rich in total protein (66%, 68% and 71% for E. coli, B. cereus and B. subtilis, respectively). The chemical oxygen demand and biological oxygen demand were reduced significantly by the growth of bacteria. The protein produced contained all essential amino acids for ruminant feed.

Utilization for lactic acid production with a new acid hydrolysis of ram horn waste

The use of ram horn hydrolysate (RHH) as a substrate for lactic acid production was investigated using Lactobacillus casei. For this purpose, first RHH was produced. Ram horns were hydrolyzed by treating with acids (6N-H2SO4 and 6N-HCl) and neutralizing the solutions. The amounts of protein, nitrogen, ash, some minerals, total sugars, total lipids and amino acids of the RHH were determined. The effect of different concentrations (1-10% v/v) of RHH on the production of biomass, lactic acid concentration and sugar consumption was investigated, and a concentration of 6% RHH was found to be optimal. The content of lactic acid in the culture broth containing 6% RHH (44 g x l(-1)) for 26 h was 22% higher than that of the control culture broth (36 g x l(-1)). From this result, RHH was demonstrated to be a suitable supplement for lactic acid production, a use that would resolve a local environmental problem.

Production of citric acid from ram horn hydrolysate by Aspergillus niger

Abstract Ram horn hydrolysate (RHH) was used as a substrate for the microbial production of citric acid using Aspergillus niger NRRL 330 in a submerged culture. Ram horns were hydrolyzed by treating with acid (6N–H 2 SO 4 ) and neutralizing the solution. The amounts of protein, nitrogen, ash, some minerals, total sugars, total lipids and amino acids of the RHH were determined. The effect of different concentrations (1–10% v/v) of RHH on the production of biomass was investigated and a concentration of 8% RHH was found to be optimal. The content of citric acid in the culture broth containing 8% RHH (78 g/l) for 6 d was 26% higher than that of the control culture broth (62 g/l). From this result, RHH was demonstrated to be a suitable substrate for citric acid production. RHH may be a valuable supplement in biotechnology.

Effects of extremely low magnetic field on the production of invertase by Rhodotorula glutinis

Invertase is an important enzyme used in many fields especially in food industry to produce fructose syrups. The current study focused on increasing invertase production by exposing Rhodotorula glutinis to extremely low magnetic fields (ELMF; 0 and 7 mT). For this purpose, the microorganism was allowed to grow in normal magnetic field and ELMF for 72 hours at the same temperature (24 ± 2°C). The fermentation was carried out in submerged culture for 120 hours. The results showed that invertase production is strongly dependent on the growth conditions of the microorganism. Both of the different magnetic fields applied to R. glutinis increased invertase production ranged from 48%-67% when compared with the control. On the other hand, ELMF treatment increased biomass formation about 14%-28% when compared with the control. As a result, magnetic field treatment could effectively be used in the production of invertase by R. glutinis.

Enhancement of lactic acid production with ram horn peptone by Lactobacillus casei

Ram horns are a waste material from the meat industry. The use of ram horn peptone (RHP) as a supplement for lactic acid production was investigated using Lactobacillus casei. For this purpose, first, RHP was produced. Ram horns were hydrolysed by treating with acids (3 M H2SO4 and 6 M HCl) and neutralizing the solutions to yield ram horn hydrolysate (RHH). The RHH was evaporated to yield RHP. The amounts of protein, nitrogen, ash, some minerals, total sugars, total lipids and amino acids of the RHP were determined and compared with a bacto-tryptone from casein. When the concentrations (1–6% w/v) of the RHP were used in bacterial growth medium as a supplement, 2% RHP (ram horn peptone medium) had a maximum influence on the production of lactic acid by L. casei. The content of lactic acid in the culture broth containing 2% RHP (43 g l−1) grown for 24 h was 30% higher than that of the control culture broth (33 g l−1) and 10% higher than that of 2% bacto-tryptone (39 g l−1). RHP was demonstrated to be a suitable supplement for production of lactic acid. This RHP may prove to be a valuable supplement in fermentation technology.

Highly enantiomeric reduction of acetophenone and its derivatives by locally isolated Rhodotorula glutinis.

Ninety isolates of microorganisms belonging to different taxonomical groups (30 bacteria, 20 yeast, and 40 fungi) were previously isolated from various samples. These isolates were screened as reducing agents for acetophenone 1a to phenylethanol 2a. It was found that the isolate EBK-10 was the most effective biocatalyst for the enantioselective bioreduction of acetophenone. This isolate was identified as Rhodotorula glutinis by the VITEK 2 Compact system. The various parameters (pH 6.5, temperature 32 degrees C, and agitation 200 rpm) of the bioreduction reaction was optimized, which resulted in conversions up to 100% with >99% enantiomeric excesses (ee) of the S-configuration. The preparative scale bioreduction of acetophenone 1a by R. glutinis EBK-10 gave (S)-1-phenylethanol 2a in 79% yield, complete conversion, and >99% ee. In addition, R.glutinis EBK-10 successfully reduced various substituted acetophenones.

Enhanced production of prodigiosin by Serratia marcescens MO-1 using ram horn peptone

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.

Production of (R)-1-phenylethanols through bioreduction of acetophenones by a new fungus isolate Trichothecium roseum.

A total of 120 fungal strains were isolated from soil samples and evaluated in the bioreduction of substituted acetophenones to the corresponding (R)-alcohols. Among these strains, isolate Trichothecium roseum EBK-18 was highly effective in the production of (R)-alcohols with excellent enantioselectivity (ee > 99%). Gram scale preparation of (R)-1-phenylethanol is reported.