Suryadarma, Prayoga
Journal of Tropical Life Science

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Glycerol Utilization as Substrate for Ethanol Production in Escherichia coli Recombinant under an Aerobic Condition Pranata, Wahyu Suradi; Suryadarma, Prayoga; Mangunwidjaja, Djumali
Journal of Tropical Life Science Vol 8, No 1 (2018)
Publisher : Journal of Tropical Life Science

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.11594/jtls.08.01.14

Abstract

The utilization of glycerol as a substrate for ethanol production in E. coli recombinant harboring ethanologenic gens (PDC and ADHB) under aerobic conditions was investigated. This research was conducted by using E. coli BW25113 which compared the growth characteristics on glycerol and glucose as carbon source. E. coli can grow well on both substrates and it consumed glycerol faster than glucose. On glucose, E. coli occurred overflow metabolism that indicated by high acetate accumulation. Meanwhile, on substrate of glycerol the acetate accumulation could be reduced. Using glycerol substrate on E. coli increased piruvate accumulation, comparing with glucose. Therefore, the growth characteristic of glycerol was more effective. In E. coli ∆pta/pHfdh/pTadhB-pdc utilized glycerol substrate was able to accumulate pyruvate as intermediate metabolite for produce 2.18 gL-1 ethanol.
THE EFFECT OF PRETREATMENT OF MICROWAVE HEATING ON EFFICIENCY OF HYDROLYSIS TIME AND α-CELLULOSIC CHARACTERISTICS OF PALM OIL WASTE BIOMASS Kasim, Fitriani; Syamsu, Khaswar; Setyaningsih, Dwi; Suryadarma, Prayoga; Sudirman, Sudirman
Jurnal Sains Materi Indonesia Vol 20, No 1: OCTOBER 2018
Publisher : Center for Science & Technology of Advanced Materials - National Nuclear Energy Agency

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (1072.334 KB) | DOI: 10.17146/jusami.2018.20.1.5408

Abstract

THE EFFECT OF PRETREATMENT OF MICROWAVE HEATING ON EFFICIENCY OF HYDROLYSIS TIME AND α-CELLULOSIC CHARACTERISTICS OF PALM OIL WASTE BIOMASS. This research is underlied by the needs of various industries for alpha cellulose, especially for the needs of raw material for cellulose nanocristalline, from fiber derived from the most potential waste biomass in Indonesia, namely oil palm empty fruit bunches (OPEFB) and mesocarp fibers. This study aims to find out the effect of pretreatment by microwave heating on the efficiency of hydrolysis time and alpha cellulose characteristics from palm oil waste biomass. To produce alpha cellulose, acid hydrolysis is commonly used with the multistage pulping process method, where the fiber is dissolved into HNO3 mixed acid, 3.5% and NaNO2, heated at a temperature of 90 oC for 2 hours, hydrolyzed and delignified to remove lignin and bleached, then separated from betha and gamma cellulose by dissolving it with NaOH 17.5%. In this study, a preliminary treatment (pretreatment) with microwave heating was carried out before the fiber was hydrolyzed so that the hydrolysis process was more efficient without reducing the characteristics of the alpha cellulose produced. The research results showed that pretreatment with microwave heating can streamline the hydrolysis time from 2 hours to 1 hour, without reducing its characteristics, where the degree of fiber crystallinity (XRD) and the yield of alpha cellulose remain high. Microwave heating with 450 watts for 5 minutes (treatment A) is better than 300 watts of heating for 10 minutes (treatment B). From the results of the study, it can be concluded that the pretreatment with microwave heating can streamline the hydrolysis time of the fiber to obtain alpha cellulose and increase the yield of the produced alpha cellulose.