Production of β-Glucosidase from a Newly Isolated Aspergillus Species Using Response Surface Methodology

A newly isolated fungus Aspergillus niger SOI017 was shown to be a good producer of β-glucosidase from all isolated fungal strains. Fermentation condition (pH, cellobiose concentration, yeast extract concentration, and ammonium sulfate concentration) was optimized for producing the enzyme in shake flask cultures. Response surface methodology was used to investigate the effects of 4 fermentation parameters (yeast extract concentration, cellobiose concentration, ammonium sulfate concentration, and pH) on β-glucosidase enzyme production. Production of β-glucosidase was most sensitive to the culture medium, especially the nitrogen source yeast extract. The optimized medium for producing maximum β-glucosidase specific activity consisted of 0.275% yeast extract, 1.125% cellobiose, and 2.6% ammonium sulfate at a pH value of 3

Fungal bioconversion of old oil-palm trunks by enzymatic hydrolysis on development of alternate energy source

The progressive depletion of fossil fuels has been causing increasing concern on rising energy consumption and environmental issues, such as greenhouse gas emission (GHG) and global warming. Due to low productivity of oil-palm tree after 20 - 25 years, the trees passed their economic age followed by the cutting-activity for replanting. Consequently, the old oil-palm trunks are one of the most abundantly available renewable resources produced, especially by Indonesia and Malaysia. We found that the felled oil palm trunk contains large quantity of sap with high concentration of free sugar contents. The oil-palm trunk residues which are the residual substances after squeezing sap will be discharged in large quantity. Composition analysis revealed that oil-palm residues mainly consisted of 73.12% holocellulose (cellulose and hemicellulose) and 24.6% of lignin. We tried the screening of filamentous fungus which can produce high-activity enzyme against oil-palm trunk residues as feedstock of bioethanol production.  A filamentous fungus, which is Penicillium rolfsii with strong activity against oil-palm trunk residues was selected for saccharification experimental study. The result showed that higher amount of sugar production was achieved comparing to the commercial enzymes (Celluclast 1.5L and Accellerase®1500) on hydrolysis of oil palm residues, which is 1 to 2-fold of higher activity. Hence, Penicillium rolfsii have attracted a great deal of interest as oil-palm residues degrader due to their superiority activity against commercial enzymes

Construction of novel metabolic pathways with artificial enzymes

Non-fossil raw materials can be utilized for the production of useful compounds by way of microbial fermentation . Sugars are obtained from carbon fixations of plants or photosynthetic microorganisms, and are used as a carbon source for the biosynthesis of useful target compounds by genetically modified microorganisms. In order for a microorganism to produce enough target compound, techniques for optimal metabolic design must include balance of energy production/consumption, redox pathways, and intracellular carbon flow. With recent innovations in genome analysis technology and information processing technology, computational design tools that can describe more than 1000 genome-scale metabolic reactions to efficiently produce target compounds have been developed worldwide. However, the established tools are not designed to search and create biosynthetic pathways for production of non-natural compounds from fossil resources. We developed BioProV and M-path, new simulation tools that enable metabolic design for the biosynthesis of unnatural compounds. By combining these tools with enzyme engineering technology, we succeeded in expanding the scope of bioproduction targets. The first example is construction of an artificial metabolic pathway to biosynthesize isoprene. Isoprene the raw material for production of synthetic rubber that can be used in automobile tires. Currently, isoprene is industrially produced as a by-product of naphtha pyrolysis. Therefore, by establishing green isoprene production technology, dependence upon petroleum can be reduced. Isoprene is a substance that can exist within cells of many organisms as a monomer of polyisoprene rubber, and also as a structural unit of secondary metabolites. It is difficult to optimize its synthentic pathway due to shortages of intracellular ATP supply, and challenges in the introduction of improved biosynthetic pathways. In nature, isoprene is produced from mevalonic acid through a five-step reaction, but the newly constructed artificial metabolic pathway consists of just two steps from mevalonic acid to isoprene. This results in a three-fold reduction in cellular energy consumption. Furthermore, we succeeded in constructing a highly active enzyme that exhibits 10,000-fold higher isoprene-producing activity relative to natural enzymes. By introducing these artificial metabolic reactions into Escherichia coli, efficient artificial isoprene production was achieved. In addition, we have developed a microbial production system for 1,3-butadiene, another alternative source for synthetic rubber. Moreover, rationally engineered enzymes from insects and plants enzymes have resulted in the construction of an artificial pathway to benzylisoquinoline alkaloids and downstream opioid analgesics

The Effect on Intracytoplasmic Sperm Injection Outcome of Genotype, Male Germ Cell Stage and Freeze-Thawing in Mice

BACKGROUND: Intracytoplasmic sperm injection (ICSI) has been widely used to study the mechanisms of mammalian fertilization and to rescue male-factor infertility in humans and animals. However, very few systematic analyses have been conducted to define factors affecting the efficiency of ICSI. In this study, we undertook a large-scale series of ICSI experiments in mice to define the factors that might affect outcomes. METHODOLOGY/PRINCIPAL FINDINGS: We used a 5 x 3 x 2 factorial design with the following factors: mouse genotype (ICR, C57BL/6, DBA/2, C3H/He, and 129/Sv strains), type of male germ cells (epididymal sperm, elongated or round spermatids), and their freeze-thawing treatment. The efficiencies (parameters) of each developmental step were analyzed by three-way ANOVA (significance level P<0.01). The type of male germ cells affected all the four parameters observed: oocyte survival after injection, cleavage of oocytes, implantation, and birth of offspring. Genotype affected the oocyte survival, cleavage and birth rates, whereas freeze-thawing had no effects on any of the parameters. There were significant genotype/cell type interactions for oocyte survival and cleavage, indicating that they were determined by a combination of strain and germ cell maturity. Multiple comparisons revealed that spermatozoa and elongated spermatids gave better implantation and birth rates than did round spermatids, while spermatozoa and elongated spermatozoa were indistinguishable in their ability to support embryonic development. The best overall efficiency (birth rate per oocytes injected) was obtained with frozen-thawed DBA/2 strain elongated spermatids (23.2+/-4.2%). CONCLUSIONS/SIGNIFICANCE: The present study provides the first comprehensive information on ICSI using the mouse as a model and will contribute to the efficient use of materials, time, and efforts in biomedical research and clinics involving ICSI

Penicillium Rolfsii, the Potential Lignocellulolytic Fungus on Hydrolysis of Oil-palm Residues From Oil Palm Trunk as a Second Generation Biofuel Feedstock

Energy crisis involved the excessive consumption of fuels causing the increased in energy demands, oil price and depletion of fossil fuels. This has resulted in generation of high level of greenhouse gases emission. Therefore, in order to overcome these problems, alternative fuel has to be produced. This study was conducted to isolate potential fungal strains which can hydrolyze oil-palm residues as feedstock for bioethanol production. One hundred and sixty four fungal isolates were isolated from various sources and were screened for reducing sugars and protein production using submerged fermentation system. Out of these, 65 fungal strains were found capable to produce high specific activity relatively on oil-palm residues with the assay condition of temperature at 50oC for incubation time of 24 hours. Fungal isolate namely, Penicillium rolfsii was selected for subsequent study since it showed the highest capability to hydrolyze oil-palm residues comparing to other fungal strains based on time-course profile for 48 hours incubation time. Capability of Penicillium rolfsii on hydrolysis of oil-palm residues was evaluated by comparing to type strain of NBRC7735 and commercial enzymes (Celluclast 1.5L and Accellerase®1500). Conversion of these lignocellulosic oil-palm residues into fermentable sugars by enzymatic hydrolysis for bioethanol production has to be further investigated to move towards on alternative, renewable, sustainable, efficient and cost effective energy sourc

Oxaliplatin for Metastatic Colon Cancer in a Patient with Renal Failure

The efficacy, safety, pharmacokinetics, and dialysability of oxaliplatin were assessed in a hemodialysis patient with recurrent cecal cancer

Environmental Load Evaluation of Reuse Parts for Automobiles

Abstract Reuse parts are parts removed from scrap automobiles that can be still used. In general, reuse parts reduce not only the cost for replacement of failed parts but also the environmental load. This study quantitatively evaluates environmental loads, such as the amount of CO2 emission during the production of brand new parts, in order to quantify the beneficial effect of the reuse parts. The amount of CO2 emission can be calculated from the power consumption and operating time of each tool and machine employed. Reuse parts generate 0.62 kg of CO2 per automobile when produced, which corresponds to 1,212 kg per year. However, the amount of CO2 emitted from scrapping automobiles without producing new replacement parts is 3,063 kg per year. Therefore, the production of replacement parts emits three times less CO2 than scrapping