Isolation and Identification of Methylotrophic Bacteria Producing Methanol Dehydrogenase from Human Feet and Mouth

Diana Elizabeth Waturangi,Catherine Delany Nicholas,Cindy Oktavia Susanto,Maggy Thenawijaya Suhartono

doi:10.4308/hjb.18.1.11

Diana Elizabeth Waturangi, Catherine Delany Nicholas + Show 2 more

Open Access

https://doi.org/10.4308/hjb.18.1.11

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Abstract

The human feet and mouth are known as sources of methylated sulfides, which are produced by other microflora. Methylated sulfides could be oxidized by methylotrophic bacteria, which may result in odor reduction in human feet and mouth. In this study, we collected a total of 21 isolates from human feet, and 37 isolates from human mouth. These isolates were identified with biochemical test such as oxidase and catalase test and Gram staining assay. The presence of mxaF gene of methanol dehydrogenase was detected by PCR using specific primers. However, the result showed that most of the isolates did not possess mxaF gene. Hence, the methanol dehydrogenase (MDH) activity was also determined. From the total 21 isolates obtained from the feet, only 15 of them showed MDH activity whereas 23 isolates from the total 37 isolates obtained from teeth and tongue region also showed MDH activity. Isolate K25-3 (74.444 U/ml), K33-6 (79.815 U/ml), and K43-5 (69.259 U/ml) from human feet and M41L3 (135.926 U/ml), M27G2 (85.556 U/ml), and M51G1 (103.333 U/ml) from human mouth showed the highest total enzyme activity. Isolates with the highest total activity could be used for further studies such as purification of the enzyme and isolates characterization.

Highlights

Methylotrophic bacteria are aerobic bacteria that utilize one-carbon compounds, such as methane, methanol, and methylated compounds containing sulfur, as sources of carbon and energy (Hanson & Hanson 1996)
We report the isolation and identification of methylotrophic bacteria in human mouth and feet from a tropical region
Methylotrophic bacteria were isolated and stored in minimal media supplemented with 1% (v/v) methanol and Luria agar media supplemented with 0.01% (w/v) cycloheximide (Sigma-Aldrich,USA) to reduce fungi contamination (Riupassa & Suwanto 2004)

Summary

INTRODUCTION

Methylotrophic bacteria are aerobic bacteria that utilize one-carbon compounds, such as methane, methanol, and methylated compounds containing sulfur, as sources of carbon and energy (Hanson & Hanson 1996). The human mouth and feet are sources of volatile one carbon compounds such as methanethiol and dimethylsulphide. Methylotrophic bacteria occur in that habitat and utilize volatile one carbon compounds as their energy source. The enzymes of methylotrophic metabolism play an important role in methylotrophic bacteria’s ability to use one carbon compounds as energy source. One of these methylotrophic enzymes is methanol dehydrogenase (MDH). There are pyroloquinoline quinon (PQQ) and a Ca2+ ion which are bound non-covalently to each of α subunit They are both key to the action of methanol dehydrogenase (Liu et al 2006).

MATERIALS AND METHODS

RESULTS

DISCUSSION