Poly 3-hydroxybutyrate-co-3-hydroxyhexanoate films can be degraded by the deep-sea microbes at high pressure and low temperature conditions

ABSTRACT

We have isolated several poly 3-hydroxybutyrate-co-3-hydroxyhexanoate (PHBH) degradable bacteria from the deep-sea sediment samples. The isolated microbes were involved into α-, γ- Proteobacteria group and the phylum Firmicutes, which were commonly diverged in the ocean environment. Four bacterial strains, Bacillus sp. MH10, Alteromonas sp. MH53, Psychrobacillus sp. PL87 and Rheinheimera sp. PL100, were selected as more active strains for the PHBH bio-degradation at high pressure and cold temperature conditions, and showed that those strains were piezotolerant up to 20–30 MPa. Our findings indicated that the PHBH could be well degraded not only in the ocean environment, but also at the deep-sea bottom, by means of those marine microorganisms.

KEYWORDS:

• Biodegradable plastic
• cold temperature
• deep-sea bacteria
• degradation
• high pressure
• poly 3-hydroxybutyrate-co-3-hydroxyhexanoate (PHBH)

Acknowledgements

We are very grateful to the science groups of the KM16-04 cruises, the deep-sea remote operated vehicle Hyper Dolphin and MS Kaimei’s ROV operation teams, and the crews of the MS Kaimei for helping us to collect the deep-sea sediment samples. We also thank Dr. Akihiro Tame (Marine Work Japan Co.) to help the electron microscopic observations.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This study was partially supported by a Grant-in-Aid for Exploratory Research [grant number 25450121] provided by the Ministry of Education, Culture, Sports, Science and Technology of Japan (CK).