Determination of critical point of p02 L]level in the production of lactic acid by Lactobacillus rhamnosus

The study was conducted to determine the critical point of p02 level in the production of lactic acid by Lactobacillus rhamnosus. The fermentation process was successfully carried out in laboratory scale fermenteribioreactor using different p02 level (the main parameter that significantly affects the growth of L. rhamnosus and lactic acid production) together with two other parameters; the agitation rate and pH. From the result, it was observed that the best production of lactic acid with the concentration of 16.85 g L -1 or 1.68% production yield has been obtained at the operating parameters of 5% p02 level, agitation speed of 1 00 rpm and sample pH 6. The critical point of p02 was fOlUld to be between 5 and 10%

A case-control study of risk factors for bovine brucellosis seropositivity in Peninsular Malaysia

Bovine brucellosis was first reported in Peninsular Malaysia in 1950. A subsequent survey conducted in the country revealed that the disease was widespread. Current knowledge on the potential risk factors for brucellosis occurrence on cattle farms in Malaysia is lacking. Therefore, we conducted a case-control study to identify the potential herd-level risk factors for bovine brucellosis occurrence in four states in the country, namely Kelantan, Pahang, Selangor and Negeri Sembilan. Thirty-five cases and 36 controls of herds were selected where data on farm management, biosecurity, medical history and public health were collected. Multivariable logistic regression identified that Brucella seropositive herds were more likely to; have some interaction with wildlife (OR 8.9, 95% CI = 1.59–50.05); originated from farms where multiple species such as buffalo/others (OR 41.8, 95% CI = 3.94–443.19) and goat/sheep (OR 8.9, 95%Cl = 1.10–71.83) were reared, practice extensive production system (OR 13.6, 95% CI 1.31–140.24) and have had episodes of abortion in the past (OR 51.8, 95% CI = 4.54–590.90) when compared to seronegative herds. Considering the lack of information on the epidemiology of bovine brucellosis in peninsular Malaysia and absence of information on preventing the inception or spread of the disease, this report could contribute to the on-going area-wise national brucellosis eradication program

ダイズ ベータ - コングリシニン オヨビ ナタネ クルシフェリン ノ コウゾウ カコウ トクセイ ソウカン ニ カンスル ケンキュウ

京都大学0048新制・課程博士博士(農学)甲第10504号農博第1377号新制||農||882(附属図書館)学位論文||H15||N3859(農学部図書室)UT51-2003-U474京都大学大学院農学研究科応用生命科学専攻(主査)教授 内海 成, 教授 森 友彦, 教授 北畠 直文学位規則第4条第1項該当Doctor of Agricultural ScienceKyoto UniversityDA

Isolation of GSH from Baker Yeast by Ultrasonic method

The purpose of this study was to determine the effect of operating parameters such as the yeast concentration, processing temperature and isolation time on the isolation of GSH using Ultrasonic method. The disrupted cells solution was centrifuged at 12,000 rpm for 20 min and the GSH content in the supernatant was analyzed by taking the OD value of the solution using Spectrophotometer at 412 nm. To study the effect of yeast concentration, yeast solution with the concentration of 3, 6, 9 and 12 wt.% was disrupted at their original temperature for 15 sec. The result shows that the optimum value of yeast concentration is 6 wt.% where 12.93 μmol mL-1 GSH was isolated. To study the effect of processing temperature, Ultrasonic process of the 6 wt.% yeast solution was done at various values of temperature such as 19, 22, 25, 28, 30 and 40�C for 15 sec. The results indicated that, the optimum GSH isolation temperature is 22�C with the isolation of 13.53 μmol mL-1 GSH. Then, to study the effect of isolation time, the Ultrasonic process of sample with the concentration of 6 wt.% was done at 22�C for 15, 30, 45 and 60 sec. The result indicated that the optimum isolation time for the Ultrasonic process is 15 sec

Media screening and optimization of lactic acid fermentation

The screening and optimization of lactic acid production using bacteria L. rhamnosus were successfully carried out in shake flask experiment. Initially eleven variables were screened using Placket Burman Design and result indicated that, the main variables that effected were glucose and peptone. These two most significant variables were then optimized using the Central Composite Design. The correlation between those two variables was analyzed using Response Surface Methodology (RSM). The contour plot indicates that the interactions between these two variables are not much significantly different. The optimization and critical value indicate that the most ideal concentration of glucose and peptone for optimum production of lactic acid in shake flask is 9.80g/l and 9.98g/l, respectively. The maximum growth rate for these bacteria is 0.394 h-1 and the productivity is 0.630 g/g.h

Microbial treatment performance with developed bioconversion process for citric acid production from sewage treatment plant sludge

In Malaysia, Sewage Treatment Plant Sludge (STP sludge) is the largest contributor of organic pollution to water resources and soil. Its contribution is top listed (64.4%), followed by animal husbandry wastes (32.2%), agro based pollutants (1.7%) and industrial effluents (1.3%) in terms of BOD load. In this study, STP sludge was used as substrate because it is an inexpensive and easily available raw material and a good source for growth of microorganisms due to enough nutrients and trace elements present for citric acid production with optimum process conditions. Citric acid is one of the important chemicals used in various industrial processes. It is estimated that about 500,000 tons of citric acid is produced annually by fermentation of expensive raw materials like glucose and sucrose. The optimum process factors determined by central composite design (CCD) using the statistical software MINITAB from previous study were: substrate concentration of 1%; both wheat flour and glucose concentrations of 4%; fermentation period of 6 days with absence of ammonium nitrate. The strain Aspergillus niger (A-SS106), isolated and screened by another work, was used throughout the study. Evaluation of the treatment performance was done in terms of maximum citric acid production, biosolids accumulation, chemical oxygen demand (COD) removal and reduction of reducing sugar. The maximum citric acid production was 1.296 g/l on 6th day at pH 1.57 with the reduction of COD concentration from 82.5 g/l to 22.6 g/l. Reducing sugar showed a decreasing trend from the beginning but maximum decrease was observed on the last two days of the fermentation process

Growth kinetics study and process optimization of lactic acid fermentation in laboratory scale fermenter

The purpose of this research was to study the growth kinetics of Lactobacillus rhamnosus in laboratory scale fermenter and to optimize the production of lactic acid with varying certain operating conditions of fermenter. The experiment was designed by Taguchi Method using STATISTICA software to improve the process quality and to increase the lactic acid production. Three parameters have been chosen to be main parameters that effect significantly to L. rhamnosus growth that were agitation speed of the impeller, dissolve oxygen level (pO2) and pH. From comparison between the four runs, the best production of lactic acid has been achieved at lower agitation rate (cascade control, 1-500 rpm), slightly lower pO2 level (10%), and lower pH level (pH 6) with lactic acid concentration of 14.55 g/L. The maximum growth rate and productivity have been obtained at 0.5 h-1 and 0.1282 g/g.h., respectively

The influence of process parameters on lactic acid fermentation in laboratory scale fermenter

The purpose of this study was to study the influence of process parameters on the Lactic Acid Fermentation by Lactobacillus rhamnosus in laboratory scale ferrnenter. The experiment was designed by Taguchi Method using STATISTICA software. Three parameters have been chosen as the main parameters that affect significantly to the growth of L. rhamnosus; the agitation speed of the impeller, dissolve oxygen level (p02) and pH. The most influence and important parameter for the fermentation process is pH at acidic value of 6, followed by stirrer speed (rpm) and p02 even p02 supplied and rpm played similar fWlction in maintaining suitable dissolved oxygen to the cells