Operating Variables on Production of High Purity Bio-silica from Rice Hull Ash by Extraction Process

The huge amount of rice hull biomass available in Indonesia can be utilized as raw material for bio-silica production. This study investigated the production of high-purity bio-silica from rice hull ash through an alkaline extraction process. A full factorial design (FFD) was used to screen for significant effects of the observed variables. Three operating variables – acid concentration, solvent to feed ratio (RS/F), and extraction time – were investigated with the purpose of obtaining a high yield and high purity of bio-silica. Yield and purity above 96% were achieved by using pretreatment with 1 mol/L HCl. Employing an RS/F of 5 and a longer extraction time improved the bio-silica yield. The operating variable that enhanced the bio-silica yield and purity most was acid concentration. All variable interactions had an insignificant effect on purity, while two interacting variables had a significant effect on bio-silica yield. Based on the results of this study, rice crop residue can be optimally converted to a bio-silica product in terms of yield and purity by optimizing the most effective operating variables

Operating Variables on Production of High Purity Bio-silica from Rice Hull Ash by Extraction Process

The huge amount of rice hull biomass available in Indonesia can be utilized as raw material for bio-silica production. This study investigated the production of high-purity bio-silica from rice hull ash through an alkaline extraction process. A full factorial design (FFD) was used to screen for significant effects of the observed variables. Three operating variables – acid concentration, solvent to feed ratio (RS/F), and extraction time – were investigated with the purpose of obtaining a high yield and high purity of bio-silica. Yield and purity above 96% were achieved by using pretreatment with 1 mol/L HCl. Employing an RS/F of 5 and a longer extraction time improved the bio-silica yield. The operating variable that enhanced the bio-silica yield and purity most was acid concentration. All variable interactions had an insignificant effect on purity, while two interacting variables had a significant effect on bio-silica yield. Based on the results of this study, rice crop residue can be optimally converted to a bio-silica product in terms of yield and purity by optimizing the most effective operating variables

Cloning and in silico study of an endoglucanase from a thermophilic bacterium isolated from a hydrothermal vent of West Kawio, Sangihe‐Talaud waters, North Sulawesi, Indonesia

Endoglucanase is used in industries that apply high temperatures, such as bioethanol, detergent, paper, and animal feed industries. Most available endoglucanases have very low stability at high temperatures. Therefore, this study aimed to identfy a new thermostable endoglucanase that is able to maintain its actvity at high temperatures. Five isolates of thermophilic bacteria were previously isolated from the hydrothermal vent of West Kawio, Indonesia. Among them, the DSI2 isolate showed the highest endoglucanase actvity, and was identfed and named as Bacillus safensis DSI2. The EgDSI2 gene was cloned from B. safensis DSI2. EgDSI2 is 1851 bp long encoding a protein of 616 amino acids. The encoded protein, EgDSI2, has high sequence identty to other B. safensis endoglucanases and was predicted with the Compute pI/Mw tool to be 69.41 kDa. EgDSI2 was high in hydrophobic amino acids. The enzyme had higher percentage of Ala andPro, and lower percentage of Gly compared to thermolabile endoglucanases from two Bacillus species. EgDSI2 harbored a catalytc domain belonging to glycosyl hydrolase family 9 (GH9) and a type 3 cellulose‐binding domain (CBM3). Propertes of endoglucanases with GH9‐CBM3 modular organizaton include actvity over a wide pH range, high optmum temperature, and thermostablity. Therefore, EgDSI2 has potental applicatons in the industries

Extracellular β-Glucosidase Production from bglp15.2 Gene Carrying Inulinase Signal Peptide in Saccharomyces cerevisiae BY4741

One of the important enzymes in cellulase complex is β-glucosidase. In this research, adding signal peptide of inulinase gene from Kluyveromyces marxianus, cloning, and expressing of bglp15.2 gene in S. cerevisiae BY4741 had been done. Gene of bglp15.2 encoding β-glucosidase has 90% identity to nucleotide sequence of Shewanella frigidimarina NCIMB 400 bacteria. Adding nucleotide sequence of signal peptide was aimed to secrete β-glucosidase and had been done with PCR (Polymerase Chain Reaction) method. The addition of nucleotide sequence of signal peptide in bglp15.2 gene had been done succesfully that indicated from nucleotide sequencing result and the increment of amplicon band size in electroferogram of the last addition PCR step. The bglp15.2 and bglp15.2INU gene (the bglp15.2 gene that has signal peptide nucleotide sequence) were cloned in Escherichia coli DH5α using pGEM-T-Easy vector and pBEVY-GL shuttle vector. The pBEVY-GL shuttle vector was used for transforming S. cerevisiae BY4741 with bglp15.2 and bglp15.2INU. The recombinant S. cerevisiae BY4741 carrying bglp15.2INU gene and growing in 48 hours had extracellularly β-glucosidase enzyme activity of 0,0178 U/ml and the intracellularly activity was 0,0181 U/ml. The  β-glucosidase enzyme without signal peptide was not secreted. With K. marxianus inulinase signal peptide, about 50% Bglp15.2INU protein could be secreted. The protein molecular weight of secreted Bglp15.2INU was 44 kDa in SDS-PAGE result

Cloning and in silico studies of lipase gene of a thermophilic bacteria isolated from the hydrothermal vent area of Kawio, North Sulawesi

Underwater volcano is an example of a natural habitat of thermophilic bacteria, such as hydrothermal vent Kawio in North Sulawesi. The focus of this research was to screen the bacterial isolates originally from hydrothermal vent Kawio for the production of thermostable lipase. In this study, the lipase gene from the selected isolate was cloned, sequenced, and in silico analysis was performed to predict the characteristics of the lipase protein. One of three isolates examined, showed a positive reaction. Phylogenetic analysis of 16S rRNA gene showed that the isolate was a novel bacteria closely related to Bacillus safensis strain FO-26b with 96,87% homology. Amino acid sequence analysis of the lipase showed similarity between lipase of Bacillus pumilus strain B106 with 98% homology. Further analysis at the protein level indicated that the lipase isolated from marine water was a member of family I.4 of ‘true lipase’ group

Integration Stability of sHBsAg-Multi Expression Cassettes in Pichia pastoris GS115 during Methanol Induction

Hepatitis B is the major health problem worldwide including in Indonesia. Vaccination is the best prevention strategy for the disease. For the purpose of vaccine development and to decrease drug import, production of Hepatitis B Virus (HBV) small surface antigen (sHBsAg) from Indonesian HBV subtype is needed. The recombinant protein production can be conducted by integrating multi expression cassettes of sHBsAg gene in Pichia pastoris chromosome using gene replacement method. Such integration method turns out to allow loss of foreign gene from chromosome by excisional recombination-mediated looping out. This research was aimed to determine integration stability of four copies of sHBsAg expression cassette in P. pastoris GS115 chromosome inducted with 2% methanol in FM22 medium. The methanol induction was conducted twice at 63-h and 75-h. Integration stability determination was conducted qualitatively using PCR and quantitatively using qPCR absolute quantification. A band of 208 bp with similar intensity was observed after amplification of genomic DNA. All samples generated the same Ct value of around 22 with four copies of sHBsAg gene per genome. The result from this experiment shows that integration of four copies of sHBsAg expression cassette in P. pastoris GS115 chromosome is stable during methanol induction

Hybrid Hydrothermal Carbonization and Ultrasound Technology on Oil Palm Biomass for Hydrochar Production

The hybrid hydrothermal carbonization and ultrasound technology (HHTC-Us) efficiently utilizes the function of both ultrasounds-assisted and hydrothermal carbonization for hydrochar production. The HHTC-Us of oil palm residues plays an essential role in hydrochar production. Hydrochar is a carbon-rich material potentially produced from oil palm biomass, which has gained great interest due to its unique properties. Four main topics were highlighted: the production of crude palm oil and impacted biomass residue generation, properties and potential values of oil palm biomass conversion as hydrochar, hybrid hydrothermal carbonization reaction routes, and processing parameters that affect the HHTC-Us technology. The review elucidates the promising production process or modification of hydrochar from oil palm biomass residues through hybrid technology. The technology potentially enhanced sustainability, creating challenges and new opportunitie

Bioethanol Production from Sugarcane Bagasse Using Neurospora intermedia in an Airlift Bioreactor

Bagasse as solid waste in sugarcane industry can be utilized as one of the potential raw materials in the bioprocess industry. This research aims to investigate the conversion of bagasse to bioethanol using simultaneous saccharification and fermentation in an airlift bioreactor. Neurospora intermedia was used as a biological agent that carried out the saccharification and fermentation of sugarcane bagasse simultaneously for bioethanol production. Cell morphology of N. intermedia in the form of pellet was required to provide free movement in the axial flow of airlift bioreactor. The medium pH strongly affects the morphological shape of N. intermedia. Therefore, the formation of good pellets of inoculum was observed under acidic conditions, i.e. pH 3.0 – 3.5. The effect of the initial concentration of nutrient on the inoculum growth was also investigated. Inoculums cultured in potato dextrose broth (PDB) medium with a half the strength of the common nutrient concentration of PDB qualitatively indicated good growth in terms of the size and density of cells. The inoculums with good morphological form were fed into the airlift bioreactor, which already contained a liquid medium with initial pH of 3.5 and also contained pre-treated bagasse. In experiments using the airlift bioreactor, the pre-treated bagasse was added to various nutrient concentrations of the PDB infusion medium. The highest bioethanol production from bagasse was monitored in the medium culture of half strength PDB infusion. The yield of bioethanol obtained from total sugarcane bagasse and PDB in an air lift bioreactor achieved approximately 40%, which has an infusion medium with a half-strength PDB and initial pH of 3.0