Recycling of Bakery Waste as an Alternative Carbon Source for Rhamnolipid Biosurfactant Production

A mixed microbial culture able to transform alachlor at a concentration of 50 μg ml-1was obtained from alachlor-treated soil after an enrichment period of 84 days. The microbial community was composed of seven strains of bacteria. No single isolate was able to utilize alachlor as a sole source of carbon. There was no alachlor left in the enriched culture after a 14-day incubation, but only 12% of the14C-ring-labeled alachlor was converted to14CO2through ring cleavage during 14 days in the basal medium amended with alachlor as a sole carbon source. The presence of sucrose as an alternative carbon source decreased the mineralization potential of the enriched culture, but sucrose increased the mineralizing ability of a three-member mixed culture. Thin-layer chromatographic analysis showed that there were four unidentified metabolites of alachlor produced by the enriched culture. Sucrose decreased the amount of two of the four metabolites. The absence of a noticeable decline in radioactivity beyond the initial 12% suggested that the side chain of alachlor was utilized as carbon source by the enriched culture. Little difference in radioactivity between growth medium and cell-free supernatant of the growth medium suggested that the carbon in the ring was not incorporated into the cells of the degrading microorganisms.

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Poly-β-Hydroxybutyrate (PHB) Production By Amylolytic Micrococcus sp. PG1 Isolated From Soil Polluted Arrowroot Starch Waste

Indonesian Journal of Biotechnology ◽

10.22146/ijbiotech.8634 ◽

2015 ◽

Vol 19 (1) ◽

pp. 56

Author(s):

Sebastian Margino ◽

Erni Martani ◽

Andriessa Prameswara

Keyword(s):

Carbon Source ◽

Internal Energy ◽

Organic Polymer ◽

Ftir Analysis ◽

Phb Production ◽

Alternative Carbon Source ◽

Arrowroot Starch ◽

Physiological Characters

Poly-β-hydroxybutyrate (PHB) production from amylolytic Micrococcus sp. PG1. Poly-β-hydroxybutyrate(PHB) is an organic polymer, which synthesized by many bacteria and serves as internal energy. PHB ispotential as future bioplastic but its price is very expensive due to glucose usage in PHB industry. Thedevelopment of PHB production using starch as an alternative carbon source has been conducted to reducethe dependence of glucose in PHB production. In this study, amylolytic bacteria from arrowroot processingsite were screened quantitavely based on amylase specifi c activity and PHB producing ability. The result of thestudy showed that among of 24 amylolytic isolates, 12 isolates of them were able to accumulate PHB rangedfrom 0,68-11,65% (g PHB/g cdw). The highest PHB production from substrate arrowroot starch was PG1 andafter optimization resulted in increasing of PHB production up to 16,8% (g PHB/g cdw) 40 hours incubationtime. Based on morphological, biochemical and physiological characters, the PG1 isolate was identifi ed asMicrococcus sp. PG1. Result of the FTIR analysis of produced polymer by Micrococcus sp. PG1 was indicatedas poly-β- hydroxybutyrate (PHB)

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