Mitsuokella Jalaludinii Research Articles

Optimization of carbon and nitrogen sources for phytase production by Mitsuokella jalaludinii, a new rumen bacterial species.

The effects of different carbon and nitrogen sources on phytase production by Mitsuokella jalaludinii were evaluated and the optimization of rice bran (RB) and soybean milk (SM) concentrations in the medium for phytase production was also determined. Replacement of glucose, cellobiose and starch in MF1 medium by RB or palm kernel cake and replacement of trypticase peptone and yeast extract in the medium by SM or enzymatic digested soybean milk significantly increased the phytase production by M. jalaludinii. The optimal concentrations of RB and SM in the medium for phytase production were 15% RB and 20% SM or 20% RB and 10% SM or 20% RB and 20% SM and the phytase activities in the media were 12.53, 12.93 and 12.75 U g-1 culture broth, respectively. The high production of phytase by M. jalaludinii warrants further research to increase its yield by genetic manipulation for commercial application.

Mitsuokella jalaludinii sp. nov., from the rumens of cattle in Malaysia.

Five strains of phytase-producing, gram-negative, non-spore-forming, non-motile, small, stout, rod-shaped, strictly anaerobic, fermentative bacteria were isolated from the rumens of cattle in Malaysia. All five strains had morphological, physiological and biochemical features in common. Although these strains had many physiological and biochemical characteristics that were identical to those of the Mitsuokella multacida type strain (ATCC 27723T), they could be distinguished from this species by means of the following characteristics: a smaller cell size (1.2-2.4 microm long and 0.6-0.8 microm wide); a lower final pH value (3.8-4.0) in peptone/yeast extract/glucose broth; inhibition by 0.001% brilliant green; insensitivity to kanamycin (100 microg ml(-1)) and penicillin (10 microg ml(-1)); a higher optimum growth temperature (approx. 42 degrees C); the ability to grow at 45 and 47 degrees C; the ability to ferment glycerol, sorbitol and amidon; and the inability to ferment mannitol, rhamnose, D-tagatose and melezitose. The G+C content of the type strain (M 9T) of these five strains was 56.9 mol%. Analysis of the 16S rRNA gene sequence of type strain M 9T indicated that the strain falls within the genus Mitsuokella. The sequence similarity between type strain M 9T and Mitsuokella multacida was 98.7%. The DNA-DNA relatedness between type strain M 9T and Mitsuokella multacida type strain DSM 20544T (= ATCC 27723T) was 63.8%, indicating that, in spite of a high level of similarity for the 16S rRNA gene sequence, type strain M 9T is independent of Mitsuokella multacida at the species level. On the basis of these results, a new species, Mitsuokella jalaludinii sp. nov., is proposed for these strains. The type strain is M 9T (= DSM 13811T = ATCC BAA-307T).