Simultaneous co-Saccharification and Fermentation of Sago Hampas for Bioethanol Production

Abundance of lignocellulosic biomass provides a good solution to the demands of energy crops in producing biofuel like biodiesel and bioethanol. In this study, bioethanol was produced from sago hampas via the Simultaneous co-Saccharification and Fermentation (Sc-SF) process, at 2.5% and 5.0% (w/v) solid loadings. The processing step in Sc-SF is virtually similar to that of Simultaneous Saccharification and Fermentation (SSF). However, during Sc-SF, two enzymes, amylase and cellulase, were added for the co-saccharification of sago starch and fiber. In addition, Saccharomyces cerevisiae was used to ferment the sugars in the hydrolysates. The Sc-SF samples were analyzed for carbohydrate residues, ethanol and acetic acid using the dinitrosalicylic (DNS) acid assay and High Performance Liquid Chromatography (HPLC). Results showed that the Sc-SF of the sago hampas showed high efficiencies of hydrolysis and ethanol production within the first 6 hours of fermentation. Highest  glucose production was at 37.86 g/l for the 5.0% sago hampas load and 17.47 g/l for 2.5% sago hampas load. The highest ethanol production was observed in the broth with 5.0% sago hampas, with the theoretical yield of 80.50%. Meanwhile, the highest bioethanol yield in the sample with 2.5% sago hampas was 73.19%. This study indicated that there is feasibility of bioethanol production via Sc-SF from starch rich agricultural residues such as sago hampas

Sequential saccharification and fermentation of corn stover for the production of fuel ethanol using wood-rot fungi, Saccharomyces cerevisiae and Escherichia coli K011

World oil consumption for energy and transportation applications has increased tremendously over the past decades as the world population grew, and more countries becoming industrialized. Even domestic products like plastics, chemicals, toiletries, clothes, food packaging, automobile parts and building materials are made from petrochemicals. In the United States, world\u27s number one oil consumer, approximately 70% of crude oil goes to the transportation sector. To supplement these fossil based fuels, several ethanol-gasoline blends are currently in the market, and since 2006, a massive increase in the utilization of ethanol is reported in the United States, and this trend is also observed globally. While the present first generation fuel ethanol are produced mainly from sugary and starchy feedstock, numerous efforts are underway in the research, development and production of second generation bioethanol that are derived from lignocellulosic biomass. The latter platform has not fully matured due to the various process and economic challenges in efficiently producing market friendly ethanol from lignocellulosic biomass. Therefore, it is imperative to develop means of bioprocesses that may reduce cost associated with lignocellulosic ethanol production. In our study, we aim to develop a sequential biological process that converts cellulosic materials into fermentable sugars and ultimately ethanol as a transportation fuel. We performed solid state fermentation at ambient conditions to induce lignocellulolytic activities from three fungal species, namely Phanerochaete chrysosporium, Gloeophyllum trabeum and Trichoderma reesei. We cultivated each of the fungal species on pure cellulose and corn stover to induce the secretion of cellulases, hemicellulase and lignolytic enzymes via solid state fermentation for several days. Corn stover was chosen as the main material as it is one of the most abundant agricultural residues. The mold mediated processes liberate simple carbohydrates, suitable substrates for downstream microbial utilization. Next, we performed simultaneous saccharification and fermentation (SSF) of the cellulosic materials to produce more sugars that are converted to ethanol. Prior to the SSF studies on the corn stover, we initially performed enzymatic studies of these fungal species on pure cellulose to evaluate their in situ enzyme production and hydrolytic abilities. Filter paper was used in the screening in accordance to the recommendations of several previously reported studies. The efficiency of the fungal species in saccharifying the filter was compared against a low dose (25 FPU/g cellulose) of a commercial cellulase. Fermentation was achieved by using the yeast Saccharomyces cerevisiae. Total sugar, cellobiose and glucose concentrations were monitored during the fermentation period, along with three main fermentation products, namely ethanol, acetic acid and lactic acid. Results indicated that the most efficient fungal species in saccharifying the filter paper was T. reesei with 5.13 g/100 g filter paper of ethanol being produced at days 5, followed by P. chrysosporium at 1.79 g/100 g filter paper. No ethanol was produced from the filter paper treated with G. trabeum throughout the five day fermentation stage. Acetic acid was only produced in the sample treated with T. reesei and the commercial enzyme, with concentration 0.95 g and 2.57 g/100 g filter paper, respectively at day 5. Next, we performed enzymatic saccharification of corn stover using P. chrysosporium and G. trabeum. Subsequent fermentation of the saccharification products to ethanol was achieved via the use of Saccharomyces cerevisiae and Escherichia coli K011. During the SSF period with S. cerevisiae or E. coli, ethanol production was highest on day 4 for all samples inoculated with either P. chrysosporium or G. trabeum. For the corn stover treated with P. chrysosporium, the conversion of corn stover to ethanol was 2.29 g/100 g corn stover for the sample inoculated with S. cerevisiae, whereas for the sample inoculated with E. coli K011, the ethanol concentration was 4.14 g/100 g corn stover. While for the corn stover treated with G. trabeum, the conversion of corn stover to ethanol was 1.90 g and 4.79 g/100 g corn stover for the sample inoculated with S. cerevisiae and E. coli K011, respectively. Other fermentation co-products, such as, acetic acid and lactic acid were also recorded. Acetic acid production ranged between 0.45 g and 0.78 g/100 g corn stover for the samples under different fungal treatments, while no lactic acid production was detected throughout the 5 days of SSF. In the later stages of our study, we further explore the coupling of mild chemical (dilute NaOH) and biological pretreatment and saccharification on the corn stover. Ethanol production was achieved via the sequential saccharification and fermentation of dilute sodium hydroxide (2% w/w NaOH in corn stover) treated corn stover using P. chrysosporium and G. trabeum. Ethanol production peaked on day 3 and day 4 for the samples inoculated with either P. chrysosporium or G. trabeum, slightly plateauing or decreasing thereafter. Ethanol production was highest for the combination of G. trabeum and E. coli K011 at 6.68 g/100 g corn stover, followed by the combination of P. chrysosporium and E. coli K011 at 5.00 g/100 g corn stover. Combination of both the fungi with S. cerevisiae generally had lower ethanol yields, ranging between 2.88 g (P. chrysosporium treated corn stover) and 3.09 g/100 g corn stover (G. trabeum treated corn stover). Acetic acid production ranged between 0.53 g and 2.03 g/100 g corn stover for the samples under different fungal treatments, while lactic acid production was only detected in samples treated with G. trabeum, throughout the 5 days of SSF. The results of our study indicated that mild alkaline pretreatment coupled with fungal saccharification offer a promising bioprocess for ethanol production from corn stover without the addition of commercial enzymes. We believe these sequential procedures are potentially applicable to various other lignocellulosic materials (i.e. switchgrass, poplar, corn cobs) and may assist in environmentally, economical and technological friendlier ethanol production processes

Simultaneous saccharification and fermentation of ground corn stover for the production of fuel ethanol using Phanerochaete chrysosporium, Gloeophyllum trabeum, Saccharomyces cerevisiae, and Escherichia coli K011

Enzymatic saccharification of corn stover using Phanerochaete chrysosporium and Gloeophyllum trabeum and subsequent fermentation of the saccharification products to ethanol by Saccharomyces cerevisiae and Escherichia coli K011 were achieved. Prior to simultaneous saccharification and fermentation (SSF) for ethanol production, solid-state fermentation was performed for four days on ground corn stover using either P. chrysosporium or G. trabeum to induce in situ cellulase production. During SSF with S. cerevisiae or E. coli, ethanol production was the highest on day 4 for all samples. For corn stover treated with P. chrysosporium, the conversion to ethanol was 2.29 g/100 g corn stover with S. cerevisiae as the fermenting organism, whereas for the sample inoculated with E. coli K011, the ethanol production was 4.14 g/100 g corn stover. Corn stover treated with G. trabeum showed a conversion 1.90 and 4.79 g/100 g corn stover with S. cerevisiae and E. coli K011 as the fermenting organisms, respectively. Other fermentation co-products, such as acetic acid and lactic acid, were also monitored. Acetic acid production ranged between 0.45 and 0.78 g/100 g corn stover, while no lactic acid production was detected throughout the 5 days of SSF. The results of our experiment suggest that it is possible to perform SSF of corn stover using P. chrysosporium, G. trabeum, S. cerevisiae and E. coli K011 for the production of fuel ethanol

Molecular Characteristics of Vibrio Cholerae 01 from Miri, Sarawak

The purpose of this case study was to evaluate the molecular characteristics of Vibrio cholerae 01 isolated during the biggest cholerae outbreak in Miri between November 1997 to April 1998. A total of 33 strains were examined. The randomly selected strains from over 1,000 fecal samples were studied for their antibiotic resistance, the occurrence of plasmids, RAPD-peR fingerprinting and the presence of the Ace, Ctxa, Ctxb and Zot genes. This study has shown that all strains were found to be resistant to four or more of the nineteen antibiotics and antimicrobial agents tested with MAR indices ranging between 0.21 to 0.74. These high MAR indexes suggest that all the strains originated from high-risk sources. The isolates exhibited high resistance to bacitracin (96.97%), cefuroxim (96.97%), cephalotin (90.91%), streptomycin (87.88%), rifampin (75.76%) and tetracycline (72.73%). The isolates in this study also demonstrated various degrees of resistance toward other antimicrobial agents used such as, carbenicillin (69.70%), amikacin (57.58%), ampicillin (54.54%), erythromycin (51.52%), nalidixic acid (51.52%), kanamycin (48.48%), oxacillin (33.33%), penicillin G (27.27%), ceftriaxone (21.21%), gentamycin (21.21%), vancomycin (21.21%) and cefoperazone (3.03%). All strains were, however, susceptible to chloramphenicol. According to the plasmid profile analysis, only one plasmid pattern was observed among the plasmids harboring isolates with the plasmid DNA bands ranging in sizes from 1.3 to 1.6 megadalton. Randomly amplified polymorphic DNA (RAPD) analysis was used.to analyze the genetic differentiation and relatedness of the 33 Vibrio cholerae 01 strains, using two arbitrary primers (GEN15003 and GEN15005), after screening a set of 10 primers. The two primers generated polymorphism in all 33 strains, producing typeable and reproducible results. The RAPD profiles revealed a wide variability and high level of DNA sequence diversity within the Vibrio cholerae 01 strains tested. This revealed no correlation with the source of isolation. The results from the RAPD-PCR fingerprinting were used to construct a dendrogram. From the dendrogram generated, three main clusters were observed and further subdivided into several subc1usters defining the genetic heterogeneity among the isolates. The detection of the specific genes by PCR yielded the following results; 32 of 33 (96.97%) isolates were positive for the Ace, C txa, Ctxb and Zot genes. Only 1 (3.03%) of the isolates exhibited the absences of the respective genes. The observations from all the investigations done on the isolates may indicate that multiple pathogenic strains of Vibrio cholerae 01, rather than a single type of infective strain cause these infections during the Miri cholera outbreak of 1997 and 1998

Presentation and characterization of novel thick-film PZT microactuators.

International audienceWe propose in this paper the characterization of a new generation of piezoelectric cantilevers called thick-films piezoelectric actuators. Based on the bonding and thinning process of a bulk PZT layer onto a silicon layer, these cantilevers can provide better static and dynamic performances compared to traditional piezocantilevers, additionally to the small dimensions

Evaluation of Potential Fungal Species for the in situ Simultaneous Saccharification and Fermentation (SSF) of Cellulosic Material

Three fungal species were evaluated for their abilities to saccharify pure cellulose. The three species chosen represented three major wood-rot molds; brown rot (Gloeophyllum trabeum), white rot (Phanerochaete chrysosporium) and soft rot (Trichoderma reesei). After solid state fermentation of the fungi on the filter paper for four days, the saccharified cellulose was then fermented to ethanol by using Saccharomyces cerevisiae. The efficiency of the fungal species in saccharifying the filter paper was compared against a low dose (25 FPU/g cellulose) of a commercial cellulase. Total sugar, cellobiose and glucose were monitored during the fermentation period, along with ethanol, acetic acid and lactic acid. Results indicated that the most efficient fungal species in saccharifying the filter paper was T. reesei with 5.13 g/100 g filter paper of ethanol being produced at days 5, followed by P. chrysosporium at 1.79 g/100 g filter paper. No ethanol was detected for the filter paper treated with G. trabeum throughout the five day fermentation stage. Acetic acid was only produced in the sample treated with T. reesei and the commercial enzyme, with concentration 0.95 and 2.57 g/100 g filter paper, respectively at day 5. Lactic acid production was not detected for all the fungal treated filter paper after day 5. Our study indicated that there is potential in utilizing in situ enzymatic saccharification of biomass by using T. reesei and P. chrysosporium that may lead to an economical simultaneous saccharification and fermentation process for the production of fuel ethanol

Simultaneous Reclamation of Sago Starch Processing Effluent Water and Rhizopus oligosporus Cultivation at Different pH Conditions

Industrial sago starch extraction from the sago palm (Metroxylon sagu) generates large volumes of wastewater, known as sago effluent that is generally discharged into nearby water bodies without proper treatment. This practice has led to severe environmental pollution that prompts the development of biotechnological treatments of sago effluent. In this study, Rhizopus oligosporus was grown in sago effluent at several initial pHs (pH 4, 5, and 6) during submerged fermentation to determine the optimum pH for high protein fungal biomass (HPFB) production while simultaneously reducing the starch content and high organic loads of sago effluent. Our results showed that the growth of R. oligosporus was the highest (3.8 g/L) when the initial pH of the sago effluent was 4. The same pH also gave the best reduction of starch, biochemical oxygen demand and chemical oxygen demand of the sago effluent following the R. oligosporus fermentations, which were 96.70%, 89.81%, and 78.30%, respectively. In addition, nitrate concentration was found to be reduced from 0.266 to 0.257 g/L, while the nitrite level dropped from 0.040 to 0.029 g/L. The present findings presented the potential of R. oligosporus for the production of HPFB as well as for treating sago effluent

Evaluation of Potential Fungal Species for the in situ Simultaneous Saccharification and Fermentation (SSF) of Cellulosic Material

Three fungal species were evaluated for their abilities to saccharify pure cellulose. The three species chosen represented three major wood-rot molds; brown rot (Gloeophyllum trabeum), white rot (Phanerochaete chrysosporium) and soft rot (Trichoderma reesei). After solid state fermentation of the fungi on the filter paper for four days, the saccharified cellulose was then fermented to ethanol by using Saccharomyces cerevisiae. The efficiency of the fungal species in saccharifying the filter paper was compared against a low dose (25 FPU/g cellulose) of a commercial cellulase. Total sugar, cellobiose and glucose were monitored during the fermentation period, along with ethanol, acetic acid and lactic acid. Results indicated that the most efficient fungal species in saccharifying the filter paper was T. reesei with 5.13 g/100 g filter paper of ethanol being produced at days 5, followed by P. chrysosporium at 1.79 g/100 g filter paper. No ethanol was detected for the filter paper treated with G. trabeum throughout the five day fermentation stage. Acetic acid was only produced in the sample treated with T. reesei and the commercial enzyme, with concentration 0.95 and 2.57 g/100 g filter paper, respectively at day 5. Lactic acid production was not detected for all the fungal treated filter paper after day 5. Our study indicated that there is potential in utilizing in situ enzymatic saccharification of biomass by using T. reesei and P. chrysosporium that may lead to an economical simultaneous saccharification and fermentation process for the production of fuel ethanol

Antibiotic resistance and plasmid profiling of Vibrio parahaemolyticus isolated from cockles (Anadara granosa) at Tanjung Karang, Kuala Selangor

A total of sixty V. parahaemolyticus strains isolated from local cockles (Anadara granosa) were investigated by their antibiotic resistance patterns and plasmid profiles. The isolates showed multiple resistances towards most of the antibiotics tested. All strains of V. parahaemolyticus isolated harbored 1-3 plasmids, with sizes ranging from 2.7 to 54 kb. All V. parahaemolyticus strains showed high multiple antibiotics in frequencies of 0.58 - 0.94 indicating that the strains were derived from high-risk sources. In addition, no particular plasmid profile was predictive of a particular pattern of antibiotic susceptibility. These findings are essential because of the suggested involvement of seafood especially shellfish and environment in transmission of this pathogen to human. Thus, indicating that seafood may be a source of food- acquired antibiotic resistant bacteria to consumer