Purification and characterization of a thermostable chitinase from Bacillus licheniformis Mb-2

Abstract

A chitinase produced by Bacillus licheniformis MB-2 isolated from Tompaso geothermal springs, Indonesia, was purified and characterized. The extracellular enzyme was isolated by successive hydrophobic interaction, anion exchange, and gel filtration chromatographies. The purified enzyme was a monomer with an apparent molecular weight of 67 kDa. The optimal temperature and pH of the enzyme were 70°C and 6.0, respectively. It was stable below 60°C for 2 h and over a broad pH range of 4.0-11.0 for 4 h. The enzyme was resistant to denaturation by urea (1 M), Tween-20 (1%) and Triton-X (1%), but unstable toward organic solvents such as dimethyl sulphoxide, DMSO, (5%) and polyethylene glycol, PEG, (5%) for 30 min. The enzyme hydrolysed colloidal chitin, glycol chitin, chitosan, and glycol chitosan. The first 13 N-terminal amino acids of the enzyme were determined as SGKNYKIIGYYPS, which is identical to those in chitinases from B. licheniformis and B. circulans.

Chitinolytic Bacteria Isolated from Chili Rhizosphere: Chitinase Characterization and Its Application as Biocontrol for Whitefly (<i>Bemisia tabaci</i> Genn.)

“…Isolate of I.21 only had activity in between pH 6 up to 8 and the optimum activity at pH 7. Chitinase activity of bacteria were generally optimum at low pH, but some bacteria also had optimum pH at neutral pH (Toharisman et al, 2005).…”

“…Chitinase activity was measured by a modified of Spindler method (Toharisman et al 2005). The crude extract of extracellular enzyme 150 µL was added to 300 µL 0.3% colloidal chitin and 150 µL l 0.1 M phosphate buffer at 37°C, pH 7.0, 120 rpm.…”

“…It is widely distributed in nature as an integument of insects and crustaceans and as a cell wall component of fungi and algae (Toharisman et al, 2005). In insects, chitin is not only synthesized by ectoderm cells of the epidermis, foregut, hindgut, trachea and salivary glands, but also by endoderm cells of the mid-gut Chitinases {poly [1, 4-(N-acetyl-ß-glucosaminide)] glycanohydrolase; EC 3.2.1.14} are a group of enzymes that able to degrade chitin directly into low-molecular weight products.…”

An extracellular antifungal chitinase from Lecanicillium lecanii: purification,properties, and application in biocontrol against plant pathogenic fungi

“…BG-11 (Bhushan and Hoondal, 1998). The chitinase produced by Bacillus licheniformis MB-2 was resistant to denaturation by urea, Tween 20, and Triton X-100, but unstable toward dimethyl sulfoxide and polyethylene glycol (Toharisman et al, 2005). In contrast, the chitinase from L. lecanii 43H showed high resistance to acetone, methanol, ethanol, and isopropanol.…”

Penapisan dan potensi bakteri endofit asal tanaman Arecaceae sebagai agens pengendali hayati cendawan Pestalotiopsis sp. penyebab penyakit bercak daun pada kelapa kopyor (Cocos nucifera) [Selection and potency of endophytic bacteria from Arecaceae as biocontrol agents of Pestalotiopsis sp. causing leaf spot diseae on kopyor coconut (Cocos nucifera)]

“…Kitinase merupakan enzim hidrolitik pendegradasi kitin yang dapat berperan sebagai antifungi pengendali hayati cendawan patogen (Fadhil et al, 2014). Kitin dimanfaatkan oleh bakteri dengan bantuan enzim ektraseluler kitinase yang merupakan metabolit primer, selanjutnya diperoleh Nasetilglukosamin sebagai sumber karbon bagi pertumbuhan bakteri, hal ini ditandai dengan terbentuknya zona bening pada media kitin agar (Toharisman et al, 2005). …”