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Recent Developments in the Bioconversion of Lignocelluloses into Ethanol . KOESNANDAR; IS HELIANTI; NIKNIK NURHAYATI
Microbiology Indonesia Vol. 2 No. 3 (2008): December 2008
Publisher : Indonesian Society for microbiology

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5454/mi.2.3.1


Ethanol has been commercially produced using sugars derived from sugarcane and corn. Recently, research has been focused on the development of thermotolerant and ethanol-tolerant yeast or bacteria that are able to produce ethanol efficiently, as well as the development of lignocellulosic materials as the carbon sources of fermentation. Utilization of lignocellulosic materials as fermentation substrate is promising since they are available in large amounts, renewable and relatively cheap. A lignocellulose biomass is a complex mixture of carbohydrate polymers. In order to develop an efficient process, there have been many attempts to obtain more efficient ways in the conversion of lignocelluloses to ethanol, including pretreatment, enzymatic hydrolysis of lignocelluloses and direct co-culture fermentation. This paper describes the production process of ethanol from starch-containing material, recent developments on the enzymatic bioconversion of lignocelluloses into sugars and their subsequent fermentation into ethanol and the possible recombination of microbes for the direct conversion of lignocelluloses into ethanol.
Production and Characterization of Thermoalkaliphilic Xylanase from Bacillus halodurans CM1 on Degumming Process of Ramie (Boehmeria nivea L.Gaud)Fiber as Textile Raw Material DEWI NANDYAWATI; DEA INDRIANI ASTUTI; NIKNIK NURHAYATI; ASEP RISWOKO; IS HELIANTI
Microbiology Indonesia Vol. 15 No. 3 (2021): September 2021
Publisher : Indonesian Society for microbiology

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5454/mi.15.3.3


Ramie fiber is a potential raw material to substitute imported raw materials such as cotton. Due to its higher hemicellulose content, ramie fiber required hydrolysis in a process called degumming. Enzymatic degumming is environmentally friendly compared to traditional process which using chemicals. Alkalithermophilic xylanase have high ability in hemicellulose hydrolysis. The production of xylanase was conducted by submerged fermentation of Bacillus halodurans CM1 in 20L bioreactor using Mamo and corncob medium with optimum conditions at 50°C, pH 9, 150 RPM and 1 vvm. The optimum specific activity of xylanase measured by Bailey method at 70°C and pH 9 is 475.41 U/mg. Xylanase was stable at 50°C, pH 9 and relatively stable to K+, Na2+, Co2+ and Ca2+ metal ions and Triton-X, Saba dan Tween-80 surfactants. Degumming process was carried out by immersing ramie fibers in formulated degumming solution with vlot 1:20 at 50°C, 150 RPM and 180 minutes. The enzymatic degumming process may substitute or reduce the use of chemicals due to its significant effect on ramie fiber quality. Enzymatic and chemical degumming process reduce the weight of Ramie Fiber to 7.23 %, and 7.72 %, slightly higher than enzymatic degumming 7.15%. Enzymatic degumming maintains tensile strength at 27.51 %. Whiteness index enhanced to 2.99% enzymatically and 3.49% chemically. Keywords: Bacillus halodurans CM1, enzymatic degumming, ramie fiber, textile industry, thermoalkaliphilic xylanase
Medium Optimization for Penicillin Acylase (PAc) Production by Recombinant B. megaterium MS941 Containing pac Gene from B. thuringiensis BGSC BD1 Using Response Surface Methodology FENTRI PARAMITHA PUTRI; ASTUTIATI NURHASANAH; NIKNIK NURHAYATI; IS HELIANTI; KHASWAR SYAMSU
Microbiology Indonesia Vol. 9 No. 2 (2015): June 2015
Publisher : Indonesian Society for microbiology

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5454/mi.9.2.3


Penicillin G acylase (PAc) hydrolyses of the amide bond of benzylpenicillin (Pen-G) releasing PAA and 6-APA, key intermediate in the production of various semisynthetic penicillins. In this study, we optimised the production medium of PAc by RSM using two variables (xylose as inducer and CaCl2 as divalent cations) to obtain the optimum PAc specific activity from Bacillus megaterium btpacBD1. For this purpose, combinations of five different xylose concentrations (0.13 – 0.87 %) and five different CaCl2 concentrations (0.64 – 4.36 mM) were analysed, in a total of 22 experiments. CCD used for the analysis showed that in shake flask cultivations, xylose and CaCl2 showed significant effects on PAc volumetric activity and the quadratic model was in good agreement with the experimental results (R2= 0.86 (p-value < 0.0001)). The maximum specific activity (130.669 ± 50.241 units mg protein-1) was reached when xylose and CaCl2 concentrations were 0.49% and 2.4 mM, respectively, and medium pH was around 7. Under such conditions, the activity of PAc and protein concentration achieved were 1.318 ± 0.406 units mL-1 and  0.0101 ± 0.01 mg mL-1. The shake flask validation experiments demonstrated that with such medium composition the volumetric activity, protein concentration and specific activity achieved were 1.294 ± 0.171 units mL-1, 0.0102 ± 0.0003 mg mL-1 and 125.91 ± 13.309 units mg-1, respectively. When the optimum medium composition was applied in 10 L bioreactor, the optimum volumetric activity (2.0687 ± 0.0820 units mL-1) and protein concentration (0.0078 ± 0.0008 mg mL-1) were achieved 48 h after the start of the cultivation. However, the optimum PAc specific acivity (1260.52  ± 27.5711 units mg protein-1) was achieved 18 h after the start of the cultivation.
Cloning of Lipase Gene From Thermomyces langinosus into Pichia pastoris with its Original Signal Peptide MILANI ANGGIANI; IS HELIANTI; NIKNIK NURHAYATI; ABINAWANTO ABINAWANTO
Microbiology Indonesia Vol. 11 No. 2 (2017): Juni 2017
Publisher : Indonesian Society for microbiology

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5454/mi.11.2.4


Lipase is one of the most important industrial enzymes, which is widely used in the preparation of food additives, cosmetics, and pharmaceutical industries. In the previous study, we have cloned synthetic Thermomyces lanuginosus lipase gene into Bacillus subtilis and Escherichia coli and resulting low expression for enzyme activity. The aim of this research was to construct the Thermomyces lanuginosus lipase (TLL) gene into Pichia pastoris vector expression with TLL original signal peptide. TLL gene was amplified by PCR and contained original signal peptide and then inserted into pPICZα A between XhoI and XbaI site, and transformed into competent cell E.coli DH5α. From the transformant, two of positive recombinants were analyzed by sequencing analysis. As the result,both of two recombinant have a positive target gene which has lipase gene. The correct plasmid was linearized and then was transformed in Pichia pastoris X-33 by electroporation method. Thermomyces lanuginosus synthetic gene lipase has been successfully integrated into chromosome of P. pastoris X-33, which revealed by clear zones arund the colony on Yeast extract Peptone Dextrose Tributyrin (YPD.TB) plate with zeocin. The Thermomyces lanuginosus lipase had an open reading frame of 916bp encoding TLL of 314 amino acids with theoretical molecular mass of 35 kDa. The recombinant enzyme, Thermomyces lanuginosus lipase had optimal temperature at 80˚C and optimal pH at pH 8.
The utilization of auto-inducible Plyb promoter and media optimation for cell density-dependent expression of recombinant xylanase in Bacillus subtilis DB104 Haniyya Haniyya; Dini Achnafani; Maria Ulfah; Niknik Nurhayati; Is Helianti
Microbiology Indonesia Vol. 14 No. 1 (2020): March 2020
Publisher : Indonesian Society for microbiology

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5454/mi.14.1.2


Strong promoters are one of the fundamental aspects to increase the level of gene expression, and one of approach to improve the recombinant enzyme productivity so that the efficiency of production cost for enzyme production in industrial scale can be reached. Here we assessed the application of a cell density-dependent promoter and media optimation to promote cell growth and protein expression of Bacillus subtilis without excess usage of inducers. An auto-inducible Pylb promoter that is potential to provide inducer-free enzyme production was cloned and introduced into xylanase recombinant system in B. subtilis DB104 by PCR cloning and protoplast transformation. A 200 bp target gene was successfully inserted in between xynCM1 ORF -coding for B. halodurans CM1 xylanase- and its native promoter sequence at the upstream region. The disruption of the native promoter was intended to replace the native promoter with Pylb. Recombinant xylanase gene under Pylb was successfully expressed in B. subtilis DB104 and the enzyme was produced at stationary phase. Different media with various concentrations of glucose and nitrogen were used to optimize recombinant xylanase expression. It achieved a higher level of xylanase expression compared to wild-type and recombinant xylanase with native promoter B. subtilis in media containing a 2-fold recipe of LB media thus leads to increase cell density and xylanase expression (81.461 U mL-1).
Cloning of α-L-arabinofuranosidase Genes and Its Expression in Escherichia coli: A Comparative Study of Recombinant Arabinofuranosidase Originatingin Bacillus subtilis DB104 and Newly Isolated Bacillus licheniformis CW1 MOCHAMAD NURCHOLIS; NIKNIK NURHAYATI; IS HELIANTI; MARIA ULFAH; BUDIASIH WAHYUNTARI; AGUSTIN KRISNA WARDANI
Microbiology Indonesia Vol. 6 No. 1 (2012): March 2012
Publisher : Indonesian Society for microbiology

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5454/mi.6.1.1


Arabinofuranosidase (Abfa) is one of the most important enzymes involved in degradation of lignocelullose biomass.  Two genes encoding α-L-Arabinofuranosidase (abfA), each from Bacillus subtilis DB104 (abfAa1) and an indigenous Indonesian B. licheniformis CW1 (abfAb3), were cloned by the PCR approach  and expressed in Escherichia coli. Sequences analysis of abfAa1 and abfAb3 revealed that each consists of 1721 and 1739 base pairs long DNA, respectively. Each clone contains a hypothetical open reading frame of 1503 and 1509 bp that encode an Abfa protein of 500 and 502 amino acids for abfAa1 and abfAb3, respectively. The deduced amino acid sequence of AbfaB3 shares 75% identity to that of AbfaA1. The recombinant enzymes were expressed constitutively in E. coli. Partial characterization of those enzymes revealed that the AbfaA1 and AbfaB3 were optimally active at 50 ºC and 60 ºC at pH 6, respectively. Thermostability studies of the recombinant enzymes with p-nitrophenyl α-L-arabinofuranoside at their optimal conditions showed that up to 50% AbfaA1 activity was lost after 5 h incubation at 50  ºC, whereas the AbfaB3 retained its activity over 75% after 12 h pre-incubation oat 60 ºC. This thermostability study of recombinant AbfaB3 showed for the first time that the arabinofuranosidase from B. licheniformis is a thermostable enzyme. The recombinant enzyme showed a higher optimal reaction temperature (60 ºC) in comparison to the previously reported thermostable arabinofuranosidase. The thermostable AbfaB3 has a potential to be applied to the degradation of lignocellulose biomass synergistically with thermostable xylanases, for instance in the production of xylo-oligosaccharides.
Cloning, Sequencing, and Expression of the Gene Encoding a Family 9 Cellulase from Bacillus licheniformis F11 in Escherichia coli and Bacillus megaterium, and Characterization of the Recombinant Enzymes IS HELIANTI; MARIA ULFAH; NIKNIK NURHAYATI; LLINA MULYAWATI
Microbiology Indonesia Vol. 8 No. 4 (2014): December 2014
Publisher : Indonesian Society for microbiology

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5454/mi.8.4.2


 A gene encoding cellulase belonging to the glycosyl hydrolase family 9 along with its native promoter was isolated from Bacillus licheniformis F11, cloned in Escherichia coli DH5 α and subcloned by transconjugation to Bacillus megaterium MS941. Functionality of the encoded protein was proven both in heterologous hosts, E. coli and B. megaterium. In the latter, the gene product was found in the extracellular fraction expressing a high specific activity; whereas in E. coli the protein was not secreted into the medium, and rather, showed a lower specific activity. The optimum temperature of the recombinant enzyme expressed in the hosts range from 65-75 ºC; whereas the optimum pH is 6. The recombinant enzyme was stable between 50-60 ºC and in a broad pH range (pH 5 - 9). Addition of Ca2+ and Fe3+ enhanced the enzyme activity, whereas EDTA and Cu2+  had the opposite effect. Lichenin, rather than carboxyl methyl cellulose, is the preferred substrate.