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Biphasic acid hydrolysates and enzymatic hydrolysates from carbohydrate-rich Prosopis juliflora , an invasive perennial deciduous shrub of semi-arid regions, were used for bioethanol production. Saccharomyces cerevisiae and Pichia stipitis were used for fermentation of hexoses and pentoses. P. juliflora acid hydrolysate with an initial sugar concentration of 18.70 ± 0.16 g/L was concentrated to 33.59 ± 0.52 g/L by vacuum distillation. The concentrated hydrolysate was pretreated and fermented by mono- and co-culture methods either singly or in combination with enzyme hydrolysate and ethanol yields were compared. Monoculture with S. cerevisiae (VS3) and S. cerevisiae (NCIM3455) yielded maximum ethanol of 36.6 ± 1.83 g/L and 37.1 ± 1.86 g/L with a fermentation efficiency of 83.94 ± 4.20% and 84.20 ± 4.21%, respectively, after 36 h of fermentation. The ethanol yield obtained was 0.428 ± 0.02 g/g substrate and 0.429 ± 0.02 g/g substrate with a productivity of 1.017 ± 0.051 g/L/hand 1.031 ± 0.052 g/L/h, respectively. P. stipitis (NCIM3498) yielded maximum ethanol of 24 g/L with ethanol yield of 0.455 ± 0.02 g/g substrate and a productivity of 1.004 ± 0.050 g/L/h after 24 h of fermentation. With concentrated acid hydrolysate as substrate, S. cerevisiae (VS3) produced ethanol of 8.52 ± 0.43 g/L, whereas S. cerevisiae (NCIM3455) produced 5.96 ± 0.30 g/L of ethanol. P.stipitis (NCIM3498) produced 4.52 ± 0.23 g/L of ethanol by utilizing 14.66 ± 0.87 g/L of sugars. Co-culture with S. cerevisiae (VS3) addition after 18 h of addition of P. stipitis (NCIM3498) to the mixture of concentrated acid hydrolysate and enzyme hydrolysate produced 13.86 ± 0.47 g/L of ethanol with fermentation efficiency, ethanol yield and productivity of 87.54 ± 0.54%, 0.446 ± 2.36 g/g substrate and 0.385 ± 0.014 g/L/h, respectively. Hence, it is concluded that co-culture with S. cerevisiae and P. stipitis is feasible, further scaling up of fermentation of P. juliflora substrate for bioethanol production., Competing Interests: Conflict of interestsThe authors declare that they have no competing interest., (© King Abdulaziz City for Science and Technology 2021.)

Cotton stalk, a widely available and cheap agricultural residue lacking economic alternatives, was subjected to steam explosion in the range 170-200°C for 5min. Steam explosion at 200°C and 5min led to significant hemicellulose solubilization (71.90±0.10%). Alkaline extraction of steam exploded cotton stalk (SECOH) using 3% NaOH at room temperature for 6h led to 85.07±1.43% lignin removal with complete hemicellulose solubilization. Besides, this combined pretreatment allowed a high recovery of the cellulosic fraction from the biomass. Enzymatic saccharification was studied between steam exploded cotton stalk (SECS) and SECOH using different cellulase loadings. SECOH gave a maximum of 785.30±8.28mg/g reducing sugars with saccharification efficiency of 82.13±0.72%. Subsequently, fermentation of SECOH hydrolysate containing sugars (68.20±1.16g/L) with Saccharomyces cerevisiae produced 23.17±0.84g/L ethanol with 0.44g/g yield., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

Two grams of delignified substrate at 10% (w/v) level was subjected to biphasic dilute acid hydrolysis using phosphoric acid, hydrochloric acid and sulfuric acid separately at 110 °C for 10 min in phase-I and 121 °C for 15 min in phase-II. Combinations of acid concentrations in two phases were varied for maximum holocellulose hydrolysis with release of fewer inhibitors, to select the suitable acid and its concentration. Among three acids, sulfuric acid in combination of 1 & 2% (v/v) hydrolyzed maximum holocellulose of 25.44±0.44% releasing 0.51±0.02 g/L of phenolics and 0.12±0.002 g/L of furans, respectively. Further, hydrolysis of delignified substrate using selected acid by varying reaction time and temperature hydrolyzed 55.58±1.78% of holocellulose releasing 2.11±0.07 g/L and 1.37±0.03 g/L of phenolics and furans, respectively at conditions of 110 °C for 45 min in phase-I & 121 °C for 60 min in phase-II., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

Pretreatment is a pre-requisite step in bioethanol production from lignocellulosic biomass required to remove lignin and increase the porosity of the substrate for saccharification. In the present study, chemical pretreatment of Prosopis juliflora was performed using alkali (NaOH, KOH, and NH3), reducing agents (Na2S2O4, Na2SO3) and NaClO2 in different concentration ranges at room temperature (30±2 °C) to remove maximum lignin with minimum sugar loss. Further, biphasic acid hydrolysis of the various pretreated substrates was performed at mild temperatures. Considering the amount of holocellulose hydrolyzed and inhibitors released during hydrolysis, best chemical pretreatment was selected. Among all the chemicals investigated, pretreatment with sodium dithionite at concentration of 2% (w/v) removed maximum lignin (80.46±1.35%) with a minimum sugar loss (2.56±0.021%). Subsequent biphasic acid hydrolysis of the sodium dithionite pretreated substrate hydrolyzed 40.09±1.22% of holocellulose and released minimum amount of phenolics (1.04±0.022 g/L) and furans (0.41±0.012 g/L) in the hydrolysate., (Copyright © 2013 Elsevier Ltd. All rights reserved.)

The microRNA (miRNA)-induced silencing complex (miRISC) controls gene expression by a posttranscriptional mechanism involving translational repression and/or promoting messenger RNA (mRNA) deadenylation and degradation. The GW182/TNRC6 (GW) family proteins are core components of the miRISC and are essential for miRNA function. We show that mammalian GW proteins have distinctive functions in the miRNA pathway, with GW220/TNGW1 being essential for the formation of GW/P bodies containing the miRISC. miRISC aggregation and formation of GW/P bodies sequestered and stabilized translationally repressed target mRNA. Depletion of GW220 led to the loss of GW/P bodies and destabilization of miRNA-targeted mRNA. These findings support a model in which the cellular localization of the miRISC regulates the fate of the target mRNA.

Bioethanol production from lignocellulosic materials has several limitations. One aspect is the high production cost of cellulases used for saccharification of substrate and inhibition of fermenting yeast due to inhibitors released in acid hydrolysis. In the present work we have made an attempt to achieve simultaneous cellulases production, saccharification and detoxification using dilute acid hydrolysate of Saccharum spontaneum with and without addition of nutrients, supplemented with acid hydrolyzed biomass prior to inoculation in one set and after 3 days of inoculation in another set. Organisms used were T. reesei NCIM 992, and Aspergillus niger isolated in our laboratory. Cellulase yield obtained was 0.8 IU/ml on fourth day with T. reesei. Sugars were found to increase from fourth to fifth day, when hydrolysate was supplemented with nutrients and acid hydrolyzed biomass followed by inoculation with T. reesei. Phenolics were also found to decrease by 67%.

Rice straw is one of the abundant lignocellulosic feed stocks in the world and has been selected for producing ethanol at an economically feasible manner. It contains a mixture of sugars (hexoses and pentoses). Biphasic acid hydrolysis was carried out with sulphuric acid using rice straw. After acid hydrolysis, the sugars, furans and phenolics were estimated. The initial concentration of sugar was found to be 16.8 g L(-1). However to increase the ethanol yield, the initial sugar concentration of the hydrolysate was concentrated to 31 g L(-1) by vacuum distillation. The concentration of sugars, phenols and furans was checked and later detoxified by over liming to use for ethanol fermentation. Ethanol concentration was found to be 12 g L(-1), with a yield, volumetric ethanol productivity and fermentation efficiency of 0.33 g L(-1)h(-1), 0.4 g g(-1) and 95%, respectively by co-culture of OVB 11 (Saccharomyces cerevisiae) and Pichia stipitis NCIM 3498., (Copyright © 2011 Elsevier Ltd. All rights reserved.)

Objective: A minimal cancer incidence data for Karachi, the largest city of Pakistan, is being presented here, for the years 1998-1999. The city has a population of 9,802,134; males 5,261,712 (52.6%) and females 4,540,422 (47.4%); census 1998., Methodology: A predominantly mixed (passive and active) registration system has evolved in Karachi, the data sources being the hospitals within the Karachi Division. The reported/retrieved cancer data sets at the Karachi Cancer Registry are checked, coded, computerised in an analytical format and analysed., Results: The incident cancer cases registered in Karachi, during the 2-year period, 1st January 1998 to 31st December 1999 were analysed. The age-standardised incidence rate (ASR) of cancer, all sites was 132.4/100,000 for the males. Cancer of the lung 10.8%; ASR 17.3 was the most frequently recorded malignancy, followed by oral cavity 10.5%; ASR 13.2 and larynx 5.0%; ASR 7.4. The age-standardised incidence rate (ASR) of cancer, all sites was 133.0/100,000 in the females. Cancer of the breast, 32.0%; ASR 40.7 was the most frequently recorded malignancy, followed by oral cavity 8.1%; ASR 11.7 and gall bladder 3.6%; ASR 5.5., Conclusion: The present data has been calculated with an estimated 15-20% probable under ascertainment. Tobacco-associated cancers in Karachi were responsible for 38.3% of the tumours diagnosed amongst the males. Two principal cancers, breast and oral cavity were responsible for 40.1% of the cancers in females. A rare finding was the high incidence of gall bladder cancer in the females. At present it is difficult to determine whether this indicates a genuine high risk or a selection bias. A continuous process of cancer registration to study the trends in the incidence and an adequate cancer control program are possible and essential for Pakistan and can be based on the pattern being practiced in Karachi.

The regulation of 21-hydroxylase mRNA and enzyme activity by cAMP and 12-O-tetradecanoylphorbol-13-acetate (TPA) was studied as a function of different culture conditions in bovine adrenocortical cells. Induction of 21-hydroxylase mRNA and enzyme activity was assessed after cultures were incubated with cAMP analogs. Basal 21-hydroxylase mRNA and enzyme activities were high; cAMP addition resulted in some increase in the level of mRNA, but little increase in enzyme activity. When cultures were made mitotically quiescent by using a higher starting cell density or by allowing cells to grow for a longer period before incubation with cAMP, basal mRNA and enzyme activity were low and increased greatly in response to cAMP. Other agents that raise intracellular cAMP (ACTH, prostaglandin E1, cholera toxin, and forskolin) increased 21-hydroxylase mRNA in quiescent cultures. As previously demonstrated for 11 beta-hydroxylase,21-hydroxylase mRNA induction by cholera toxin or cAMP analogs was dependent on the presence of insulin-like growth factor-I or insulin in the culture medium. When cultures were not quiescent, 21-hydroxylase mRNA and enzyme activity were highly variable, but characterized by 1) high basal levels, 2) small increases or actual decreases in response to cAMP, and 3) variable increases in response to TPA, not observed in quiescent cultures. This last effect was observed within a very narrow range of TPA concentrations (0.3-3 nM); at higher concentrations 21-hydroxylase activity decreased to values below those in the control culture. The protein kinase inhibitor staurosporine at 1-5 nM inhibited basal 21-hydroxylase enzyme activity in nonquiescent cultures by up to 80%. The probable existence of controlling factors for 21-hydroxylase expression other than cAMP suggests that the regulation of this gene differs substantially from that of the other steroid hydroxylases.

The induction of steroid 11 beta-hydroxylase and 17 alpha-hydroxylase was studied in bovine adrenocortical cell cultures in serum-free medium. In the absence of insulin-like growth factor (IGF)-I or insulin, cholera toxin failed to increase 11 beta-hydroxylase enzyme activity or messenger RNA (mRNA) levels; cholera toxin increased 11 beta-hydroxylase activity and mRNA only in the presence of 10 nM IGF-I or of higher concentrations of insulin. 17 alpha-Hydroxylase enzyme activity and mRNA, in contrast, were increased maximally by cholera toxin in the absence of insulin or IGF. We also compared the induction of 11 beta-hydroxylase and 17 alpha-hydroxylase by intracellular second messengers. When cultures were incubated with cholera toxin, cAMP analogs, forskolin, ACTH, or prostaglandin E1 in defined medium with insulin, all agents increased the mRNA levels for 11 beta-hydroxylase and 17 alpha-hydroxylase. 11 beta-Hydroxylase enzyme activity was detectable in control (insulin only) cultures and was increased to varying extents by the different agents. 17 alpha-Hydroxylase enzyme activity was undetectable in control cultures and was increased more than 50-fold by all agents. We compared the sensitivity of induction of 11 beta-hydroxylase and 17 alpha-hydroxylase enzyme activities by cAMP using serial dilutions of an equimolar mixture of N6-monobutyryl cAMP and 8-bromo cAMP. For both enzymes, the response curve was biphasic, with a maximal response in the range of 20 to 100 microM each analog, but the decline in response at higher cAMP concentrations was much more marked for 11 beta-hydroxylase than for 17 alpha-hydroxylase. The effects of activation of protein kinase C were studied in cultures incubated with 12-O-tetradecanoylphorbol-13-acetate (TPA) together with a cAMP analog mixture. TPA decreased cAMP-induced 11 beta-hydroxylase mRNA; TPA also decreased the induction of 17 alpha-hydroxylase mRNA, as previously reported. TPA caused a dose-dependent decrease in cAMP-induced 11 beta-hydroxylase enzyme activity. Angiotensin II at 0.1 to 10 microM also decreased induction of 11 beta-hydroxylase. Induction of 11 beta-hydroxylase and 17 alpha-hydroxylase is coordinately regulated by cAMP, protein kinase C, and IGF-I/insulin, but responses to these regulators differ in various respects between these two cytochrome P450 enzymes.