Isolation and Identification of Bacillus Thuringiensis From Sudanese Soils And Studies On Factors Affecting Its Growth And Sporulation

الموضوعات

زراعة

الملخص

A screening program was initiated to isolate Bacillus thuringiensis from Sudanese soils. About 434 Bacillus spp. were isolated of which 14 were found to be B. thuringiensis. Biochemical characteristics, morphological features and presence of crystalline protein within the sporulating cell were used for identifying the isolates. Biochemical tests were used to identify strains within the isolated species B. thuringiensis. The tests demonstrated that the strains belonged to different known serotypes. Two isolates belonged to serotype H-1(thuringiensis), three isolates belonged to serotype H-2(finitimus), one isolate belonged to serotype H-4 (sotto), two isolates belonged to serotype H-5 (galleriae), three isolates belonged to serotype H-6 (entomocidus), one isolate belonged to serotype H-7 (aizawai), and two isolates belonged to serotype H-8 (morrisoni). A physiological study on parameters that affect growth, sporulation and subsequently toxin production was conducted. Three isolated B. thuringiensis strains were chosen for this study, strains EA3, N10 and BR12. Different culture media were investigated with respect to growth and sporulation of isolates. Growth and sporulation were found to vary on different media. No specific medium could be pointed out as most suitable for growth and sporulation of specific strains. Effects of carbohydrate and nitrogen concentrations in the growth medium were investigated as well. It was found that all strains produced high weight of dry biomass when the concentration of glucose sugar in the medium was kept at a level of 0.4% (w/v) with various concentrations of nitrogen (yeast extract). The tested strains responded differently to air supply. As air supply increased, spore count increased by strain BR12 and the highest spore count (1.75 × 108 CFU/ml) was produced when air-to-medium ratio(v/v) was 19 : 1. Strain N10 produced highest spore count (7.8 × 107 CFU/ml) when air-to-medium ratio was 4 : 1. Any increase or decrease in aeration resulted in lower count. Strain EA3 produced highest spore counts (1.0-1.02 × 108 CFU/ml) at aeration levels of 19 : 1 and 9 : 1. Manner of addition of sugar was found to affect both pH pattern during incubation period and spore count in the final culture for all strains. Fed-batch addition (every 24 hours) of sugar resulted in survival of many growing cells, which would have been killed in case of batch addition, with subsequent better sporulation. Other parameters tested included pH of the growth medium where different starting pH values of the culture medium resulted in different influences on growth of the test strains.

روابط وملفات

التعريف والنوع

رقم الوثيقة

004c33da-d6f2-4222-8317-dd7596869d52

رقم العقد

0

نوع الوسائط

Crawler

نوع المحتوى

الرسائل العلمية

صيغة المصدر

رسائل دكتوراة

نوع الملف

pdf text

أسماء الملفات

1635997_1.pdf

بيانات النشر

ألقاب المؤلفين

[{"name_ar":"حامد احمد","title_ar":"اشراف","title_en":"Supervision"},{"name_ar":"عبدالوهاب علي","title_ar":"اعداد","title_en":"Preparation"}]

اللغة

English

المصدر والدورية

اسم المصدر

Isolation and Identification of Bacillus Thuringiensis From Sudanese Soils And Studies On Factors Affecting Its Growth And Sporulation

المحتوى والصفحات

عدد الصفحات

0

إشراف وإعداد

الإشراف

حامد احمد

الإعداد

عبدالوهاب علي

الاقتباسات الببليوغرافية