Chapter 1. Thermophilic Bacteria (Bacillus spp) for Biotechnological Applications

What is it about?

We have shown the occurrence of thermotolerant bacterial isolates from surface (sea/river) waters, fish feed, infected fish/shrimp which were normally detected from boiling hot waters of thermal springs, ice, air, and soils. We evaluated a suitable growth media for the isolation of thermophiles, their growth characteristics for various industrial and biotechnological applications and their potential utility in prevention and management of diseases. The optimal temperature for the growth of most of the thermophiles was 45ºC, except for 9 isolates and of the latter, 7 grew at 50ºC, one at 52ºC and one at 55ºC, respectively. Some of these thermotolerant bacterial isolates exhibited consistency in profuse growth at 15 psi (121°C) for 30 min while the other isolates showed inconsistency in their growth after autoclaving the cultures at 15 psi (121°C) for 30 min, and they showed development of endospores. A major 43 kDa toxin-protein as well as 15 other minor protein subunits was detected in the thermotolerant Bacillus sp.

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Why is it important?

The thermotolrant microorganisms are exploited for the benefit of humankind for the manufacture of cheese, wine, antibiotics and pharmaceuticals and to degrade pollutants, plastics and oil spills. In recent years, biotechnologists have continued to search the surface of the earth/water for microbes that might prove to be valuable in the development of new drugs, innovative processes and products for improving existing industrial processes. Normally, such thermotolerant bacteria are collected from environments with temperatures up to 75ºC and from depths extending to 2.8 kilometers below the earth’s surface. However, thermotolerant bacteria are found to exhibit growth at 110ºC in deep-sea hot springs and volcanic vents. The subsurface microorganisms survive and multiply at temperatures as high as 140ºC. Some thermotolerant bacteria are known to exist in nature at elevated temperatures and exhibit growth at both 37 and 55ºC, having a high potential in biotechnology and these bacteria are candidates for investigation regarding possible roles in industrial and biotechnological processes. In the current study, attempts were made to collect, isolate, characterize and identify thermotolerant bacteria from various sources such as fish feed, infected fish/shrimp, and sea/river waters. We further evaluated their growth characteristics for various industrial and biotechnological applications and their potential utility in prevention and management of diseases.