Hyper expression ofBacillus stearothermophilus α-amylase gene inBacillus subtilis

Summary Utilizing plasmids pUB110, pBR322 and pRG71, we have constructed a number of vectors which could be utilized for expression of cloned genes both in gram positive and gram negative bacteria. This report discusses the hyperexpression of -amylase gene ofB. stearothermophilus BR135 using these vectors.     

Transfer of transposon Tn916 from Bacillus subtilis to Thermus aquaticus

Broad host range conjugating transposon Tn916 has been introduced into the extreme thermophile Thermus by transposon transformation and transposition into the Bacillus subtilis chromosome followed by broth mating with Thermus aquaticus ATCC27634. Tetracycline resistant Thermus transconjugants were obtained at a frequency of 1.4 X 10(-7) per donor and 1.2 X 10(-7) per recipient. Transposon transfer from Thermus to Bacillus subtilis was also demonstrated in similar broth matings. Transfer characteristics were consistent with the conjugation mechanism described for Tn916 in mesophiles.     

High level extracellular secretion of thermostable α-amylase ofBacillus stearothermophilus inEscherichia coli

Summary Bacillus stearothermophilus BR135 (ATCC 29609)amy gene was cloned in pBR322 from its plasmid DNA and was subcloned in a vector useful both forB. subtilis andE. coli.E.coli HB101 harboring the plasmid pSS099 when grown in L medium in presence of 5. g/ml chloramphenicol produces 70 units/ml of extracellular -amylase. This is nearly twice that ofE.coli cells harboring pSSO76, a plasmid havingamy ofB.stearothermophilus BR135 atHindIII site of pBR322. Characteristically the protein was a 58 kd protein and cross reacted with antiserum developed against purified -amylase of BR135.     

Amylase from Lactobacillus cellobiosus D-39 isolated from vegetable wastes: Purification and characterization

An organism producing α-amylase and identified as Lactobacillus cellobiosus D-39 was recently isolated from vegetable wastes. Its amylase was purified by (NH₄)₂SO₄ precipitation and DEAE cellulose column chromatography and was obtained in crystalline form. It was fairly stable at a broadly neutral pH range and maximally active at 50°C. The molecular weight was 22 500 daltons as determined by SDS gel electrophoresis.