Isolation and Characterization of Mannanase-producing Bacillus cereus Isolated from the Hindgut of Termites

Research Article
Isolation and Characterization of Mannanase-producing Bacillus cereus Isolated from the Hindgut of Termites

Mairizal, Yetti Marlida, Mirzah and Fahmida Manin

Pakistan Journal of Nutrition, 2018, 17(3), 116-123.

Abstract

Background and Objective: Mannanase is a mannan-degrading enzyme that can be produced by microorganisms such as bacteria. Mannanase is widely used in the animal feed industry with the aim of improving the quality of feed ingredients containing high levels of mannan, such as palm kernel meal. This study aimed to isolate, characterize and produce mannanase from bacteria found in the hindgut of termites. Materials and Methods: Bacteria were isolated by culturing on solid media containing 0.5% locust bean gum for 24 h at 30°C. The mannanolytic index was then measured by the addition of 2% congo red, which was then washed with 1 M NaCl. Mannanase activity was measured by the dinitrosalicylic acid method, while the protein content was measured by the Bradford method. Results: A total of 8 isolates were obtained. The 3 isolates with the highest mannanolytic indices were selected (isolates V9, AZ and AD). Isolate V9 exhibited the highest mannanase activity of 29.50 U mL^–1 after 88 h of incubation with a specific activity of 110.32 U mg^–1. The activity of the mannanase was optimal at pH 8 and at an incubation temperature of 50°C. Based on 16S-DNA analysis, isolate V9 was identified as Bacillus cereus. Conclusion: Bacillus cereus, which is isolated from the hindgut of termites, has fairly high mannanase activity and has the potential to hydrolyse mannan in feed ingredients such as palm kernel meal.

ASCI-ID: 100-2557

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