A Study on Production of Poly-β-Hydroxybutyrate Bioplastic from Sago Starch by Indigenous Amylolytic Bacteria

• Main Authors: Nur Arfa Yanti, Langkah Sembiring, Sebastian Margino, Nurhayani H. Muhiddin
• Format: Article
• Language: English
• Published: Universitas Gadjah Mada, Yogyakarta 2015-11-01
• Series: Indonesian Journal of Biotechnology
• Online Access: http://journal.ugm.ac.id/ijbiotech/article/view/7877

<div>Bacillus sp. PSA10 and Bacillus sp. PPK5 were two indigenous strain amylolytic bacteria from Southeast</div><div>Sulawesi that have ability to produce bioplastic poly-&beta;-hydroxybutyrate (PHB) from sago starch. The study was</div><div>attempted to determine the mechanism of PHB production by bacteria amylolytic was grown on sago starchcontaining</div><div>media. Two amylolytic bacteria i.e. Bacillus sp. PSA10 and Bacillus sp. PPK5 was grown for 168 h</div><div>in a mineral salts medium with sago starch as carbon source. Growth of amylolytic bacteria was monitored</div><div>by cell dry weight. Extraction of PHB was done by N-hexane acetone-diethyl ether method and PHB content</div><div>was quantifi ed with UV spectrophotometer at 235 nm. Glucose level was determined by using kit of glucose</div><div>GOD 10&rdquo; and was quantifi ed with spectrophotometer at 500 nm. Sago starch concentration was determined</div><div>by phenol method using specthrophotometer at 490 nm. The result of the study showed that Bacillus sp.</div><div>PSA10 was produced PHB up to 66,81 % (g PHB/g cell dry weight) at 48 h and Bacillus sp. PPK5 up to 24,83</div><div>% (g PHB/g cell dry weight) at 84 h. Bacillus sp. PSA10 has ability to converse sago starch to be PHB directly</div><div>without glucose accumulation in the media, whereas Bacillus sp. PPK5 have to accumulate glucose as product</div><div>of sago starch hydrolysis to produce of PHB. PHB synthesis by Bacillus sp. PHB production on sago starch</div><div>of the Bacillus sp. PSA10 was found to be growth-associated whereas Bacillus sp. PPK5 was found to be non</div><div>growth-associated. Therefore, two indigenous amylolytic bacteria were having of difference in biosynthesis</div><div>mechanism of PHB in sago starch medium and their characteristics of PHB synthesis should be considered</div><div>in developing cultivation methods for the effi cient production of PHB.</div><div><br /></div><div>Keywords : Production, PHB, Amylolytic bacteria, Sago starch.</div>