Xylooligosaccharides (XOS) are attracting an ever-increasing amount of interest for use as food prebiotics. In this study, we used efficient membrane separation technology to convert lignocellulosic materials into a renewable source of XOS. This study revealed a dual function of nanofiltration membranes by first achieving a high yield of xylobiose (a main component of XOS) from alkali-pretreated empty fruit bunch (EFB) hydrolysate, and then by achieving a high degree of separation for xylose as a monosaccharide product. Alkali pretreatment could increase the xylan content retention of raw EFB from 23.4% to 26.9%, which eventually contributed to higher yields of both xylobiose and xylose. Nanofiltration increased the total amount of XYN10Ks_480 endoxylanase produced from recombinant Streptomyces lividans 1326 without altering its specific activity. Concentrated XYN10Ks_480 endoxylanase was applied to the recovery of both xylobiose and xylose from alkali-pretreated EFB hydrolysate. Xylobiose and xylose yields reached 41.1% and 17.3%, respectively, and when unconcentrated XYN10Ks_480 endoxylanase was applied, those yields reached 35.1% and 8.3%, respectively. The last step in nanofiltration was to separate xylobiose over xylose, and 41.3 g.L−1 xylobiose (90.1% purity over xylose) was achieved. This nanofiltration method should shorten the processes used to obtain XOS as a high-value end product from lignocellulosic biomass.

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Oil spills are one of the main causes of pollution in marine environments. Oil degrading bacteria play an important role for bioremediation of oil spill in environment. We collected 132 isolates of marine bacteria isolated from several Indonesia marine areas, i.e. Pari Island, Jakarta, Kamal Port, East Java and Cilacap Bay, Central Java. These isolates were screened for capability to degrade polyaromatic hydrocarbons (PAHs). Selection test were carried out qualitatively using sublimation method and growth assay of the isolates on several PAHs i.e. phenanthrene, dibenzothiophene, fluorene, naphtalene, phenotiazine, and pyrene. The fifty-eight isolates indicated in having capability to degrade PAHs, consisted of 25 isolates were positive on naphthalene (nap) and 20 isolates showed ability to grow in phenanthrene (phen) containing media. Further, 38 isolates were selected for dibenzothiophene (dbt) degradation and 25 isolates were positive on fluorene (flr). On the other hand, 23 isolates presented capability to degrade in phenothiazine (ptz) and 15 isolates could grow in media with pyrene (pyr). Based on homology analysis of partial 16S rDNA gene, we obtained six taxonomy classes of PAH degrading bacteria, namely α-Proteobacteria (31%), γ-Proteobacteria (43%), Firmicutes Bacilli (12%), Actinobacteria; Micrococcales (9%), Actinobacteria; Propionibacteriales (2%), and Bacteroidetes; Flavobacteriia (3%). In this research, we obtained diverse PAH degrading bacteria from marine areas.

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