SO2-Alcohol-Water Fractionation of Sugarcane Straw

Climate change resulting from fossil fuels combustion is motivating researchers to explore feasible routes to convert renewable biomass into biofuels and biochemicals for a sustainable society. Typically, biofuel is produced from corn or sugarcane but both feedstocks compete with human food supply. Thus, lignocellulosics as renewable feedstock represent a more ethical and ecofriendly approach. Sugarcane straw (SCS) is a cheap and abundantly available feedstock which potentially can be used for biofuels/biochemicals production. It can also help to mitigate environmental and health problems resulting from conventional practice of SCS burning in the fields. There are different biomass conversion technologies for production of biofuels/biochemicals. The biochemical route offers advantages of high selectivity and conversion and can also produce widely different products. Prior to fermentation, it requires a fractionation process that can produce monomeric hemicellulose sugars and a cellulosic solid residue that is easily accessible to enzymes. The SO2-ethanol-water (SEW) or AVAP® process meets these requirements. However, the viability of this process is highly dependent on efficient solvent recovery and full utilization of sugars. The SEW process produces a spent liquor stream that has only about 50% sugars as monomers. Only ethanol has been used in this process as solvent so far, and no data is available regarding alcoholysis reactions that consume solvent and potentially decrease the monomeric sugar yield. In the present thesis, the SEW process is evaluated for SCS fractionation and associated potential losses of carbohydrates and ethanol as alkyl pyranosides and by lignin alkylation. This study also investigates the effect of two other alcohols, methanol and isopropanol besides ethanol on the fractionation potential of SCS. It is the first time that a secondary alcohol is being used in the SO2-Alcohol-Water (SAW) process. The fractionation efficiency is poor using methanol but it generates methyl xylosides at a high yield. The fractionation potential of isopropanol is comparable to ethanol, however less health and safety regulations and its low process pressure make isopropanol more attractive. The kinetics of alkyl pyranoside hydrolysis in SAW liquor after solvent evaporation are measured to establish the conditions for full sugar and solvent recover

Microbiological quality of raw and smoked corbicula fluminea from selected districts in Kelantan

Corbicula fluminea (Asian Clam) or locally known as ‘etak’ among Kelantanese, is an edible freshwater bivalve found on the surface or buried in sand and mud in the shallow water of riverbeds. As a filter feeder’s, bivalves can cause bioaccumulation of hazardous organic matters, heavy metals, and microbes from the surrounding aquatic environment. This study aims to identify the current status for microbiological quality of raw and smoked Corbicula fluminea collected from several vendors in three districts in Kelantan from Jun to July 2020. A total of thirty samples were analysed for total plate count (TPC), total coliform count (TCC), faecal coliform count (FCC) and the presence of E. coli. All samples of raw Corbicula fluminea (100%) samples were found unsatisfactory for TPC, TCC, and FCC and 73.3% of the samples were positive for the presence of E. coli. About 60% of smoked Corbicula fluminea (n=15) were found unsatisfactory for TPC, TCC and FCC, and 46.7% showed the presence of E. coli. In conclusion, the microbiological quality of raw and smoked C. fluminea sold in Kota Bharu, Pasir Mas and Bachok is unsatisfactory and unsafe for consumption, and its safety remains doubtful

Biogas Production Enhancement for Kitchen Waste Digester

Production of biogas from anaerobic digestion of organic materials is an alternative source of energy. The rate of biogas production is dependent upon design as well as operational parameters of anaerobic digester. In the current study a floating drum anaerobic digester having scum breaker structure has been used to study effect of three parameters (feed concentration, sugar cane juice addition and feed temperature) on biogas production. It was investigated that about 2 cubic feet increase in biogas production occurs as feed to water ratio is increased from 1:7.5 to 1:10. With the addition of 4 liters of sugar cane juice in kitchen waste anaerobic digester running on 2Kg daily feeding, biogas production rate shoots up from 7 cubic feet per day to 20 cubic feet per day. Then the effect of sugar cane juice keeps on decreasing daily and lasts for almost for one week. A 10°C rise in feed temperature results in 4 cubic feet increase in biogas production

Heat Treatment of Spent Liquors to Recover Chemically Bound Xylose and Alcohol

SO₂–ethanol–water (SEW) and SO₂–isopropanol–water (SPW) spent liquors are obtained by fractionating sugarcane straw. The SEW and SPW liquors contain significant amounts of chemically bound xylose as ethyl xylosides (EX) and isopropyl xylosides (PX) respectively. The liquors are subjected to a constant temperature heat treatment to hydrolyze the alkyl xylosides to allow full recovery of xylose and alcohol. Complete hydrolysis of EX and PX is achieved at 121 °C in 70 and 30 min, respectively. The first-order kinetics of EX and PX hydrolysis are determined at temperatures from 100 to 121 °C. At full hydrolysis of the alkyl xylosides, the quantity of alcohol produced is greater than stoichiometric. Other sources of covalently bound alcohols in the spent liquors are identified to explain the excess alcohol produced

MITOCHONDRIAL BIOGENESIS AFTER REPEATED BOUTS OF DISUSE

Jacob L. Brown1, Richard A. Perry, Jr1., Kevin L. Shimkus2,David E. Lee1, Megan E. Rosa1, Jessica M. Cardin2, Lemuel A. Brown1, Elizabeth K. McBee1, Yasaman Sharazi-Fard2, Harry Hogan2, James D. Fluckey2, Tyrone A. Washington1 & Nicholas P.Greene1,2 1University of Arkansas, Fayetteville, Arkansas. 2Texas A&M University, College Station, Texas Muscular disuse affects a great number of people have sedentary lifestyles and/or chronic disease. Disuse has been shown to cause severe muscular atrophy and to disrupt mitochondrial quality. PURPOSE: To examine if disuse affects mitochondrial biogenesis, and if resistance exercise following bouts of unloading can promote biogenesis. METHODS: Sprague-Dawley rats were subjected to chronic disuse atrophy by hindlimb unloading (28-d, 1HU) followed by ambulatory recovery (56-d) with (1HU+EX) and without (1HU+REC) resistance exercise. To mimic repeated bouts of disuse animals were subjected to a second bout of HU (28-d, 2HU) and again allowed ambulatory recovery with (2HU+EX) or without (2HU+REC) resistance exercise. Control (CON) animals were allowed normal cage activity throughout. Samples were analyzed for Pgc-1α, Tfam, Nrf2 and Pparα gene expression by real time RT-PCR. To test if disuse impacted mitochondrial biogenesis regulators a T-Test was performed between CON and 1HU groups, to test impact of reloading and exercise data were analyzed by one-way ANOVA across all groups with α set at PRESULTS: Pgc-1α expression decreased by 59% (p=0.042) and Nrf2 by 75% (p=0.047) following disuse (1HU) compared to CON. 1HU+Ex showed a 280% increase in Pparα expression (p=0.005) as well as a 278% increase in Tfam expression (p=0.013) compared to CON. Pgc-1α, Pparα, and Tfam displayed a greater increase in expression with exercise recovery (1HU+Ex) than without (1HU+Rec). Pgc-1α showed an 80% increase in expression (p=0.05), Pparα showed a 208% increase in expression (p=0.01), and Tfam showed a 195% increase in expression (p=0.01) when comparing 1HU+Ex and 1HU+Rec. Nrf2 decreased by 61% (p=0.008) with 2HU. Expression of other biogenesis markers was not changed in the 2HU group. Neither 2HU+Ex nor 2HU+Rec were able to attenuate the loss of Nrf2 expression. CONCLUSION: A single bout of disuse significantly decreases the expression of Pgc-1α and Nrf2. 1HU+Ex promotes mitochondrial biogenesis more than 1HU+Rec. Multiple bouts of disuse decreases the expression of Nrf2. 2HU+Ex and 2HU+Rec does not attenuate the loss of Nrf2 expression. More research needs to be conducted to examine other aspects of mitochondrial quality such as mitochondrial dynamics and autophagy. Funded By National Space Biomedical Research Institut