Poster Presentation Australian Society for Microbiology Annual Scientific Meeting 2014

Identification and characterization of pectinase producing bacteria from the caeco-colic region of rabbit hind gut (#209)

Francis A. Awe 1 , Gary A. Dykes 2 , Lee Fong Siow 1
  1. School of Science, Monash University, Bandar Sunway, Selangor, Malaysia
  2. School of Chemistry, Monash University, Clayton, Victoria, Australia

The term pectinase encompasses several enzymes that break pectic substances into simpler absorbable sub-units. These enzymes are produced by microorganisms in a variety of natural environments. Pectinases are also important in paper, textile and food production as well as in the treatment of waste waters. A number of mould species have been traditionally used for the commercial production of pectinases but bacteria are increasingly recognised as having potential for this purpose. This work aimed to isolate and identify bacteria with pectinase activity from the caecum and colon of rabbit hind gut and study their relative abilities to produce three pectinases: polygalacturonase (PG); pectin lyase; (PL); and pectinmethyl esterase (PME). The total bacterial count (TC) and pectinolytic bacteria count (PC) of the rabbit ceacum and colon were not significantly different from each other (p>0.05).  The twenty seven pectinolytic bacteria isolated from both regions of the rabbit gastrointestinal tract were identified as strains of Bacillus subtilis, B. pumilus, B. megaterium, B ginsengihumi, B. licheniformis and Paenibacillus. A rapid semi-quantitative pectinolytic assay indicated that the B. subtilis strains demonstrated relatively strong pectinase production, with others strains producing moderate (B. licheniformis, B. megaterium), poor (Paenibacillus) or no (B. pumilus) pectinases. A quantitative assay demonstrated that B. subtilis 1E7 produced the highest PG and PL activity. The same assay showed that Paenibacillus 1E4 and B. megaterium 2E2 produced the highest PME activity. Of the three pectinases, PL was produced by the highest number of bacterial strains and in the relatively highest amounts. Strains, such as B. subtilis 1E7, which produce high levels of different pectinases have potential for commercial application and studies to characterize and optimize enzyme production in these strains are currently underway.