Farooq Latif - Academia.edu (original) (raw)

Papers by Farooq Latif

International Journal of Agriculture and Biology, 2014

Protein and Peptide Letters, Nov 5, 2014

Biotechnology(faisalabad), Dec 15, 2003

Protein and Peptide Letters, Nov 26, 2014

ABSTRACT The genome sequence analysis of Bacillus thuringiensis serovar konkukian S4 has shown to... more ABSTRACT The genome sequence analysis of Bacillus thuringiensis serovar konkukian S4 has shown to contain two chitinases (Chi74, Chi39) and two chitin-binding proteins (CBP50 and CBP24). The Chi74, Chi39 and CBP50 have been characterized previously. The chitin-binding protein CBP24 was cloned and heterologously expressed in Escherichia coli. The recombinant protein was purified using a Ni-NTA purification system. The purified protein was used to study its substrate binding activity using crystalline chitin variants as substrates. The Bmax and Kd values have shown that it preferably binds to β-type of the crystalline chitin at a range of pH with peak activity between 5.5-7.5. To elucidate the role of CBP24 in the chitin degradation system of S4, the purified chitinases Chi74, Chi39 along with the ChiA from Serratia proteamcualans were used in different combinations with the CBP24 and chitinolytic activity was assayed. It was shown that the CBP24 acts synergistically with chitin degradation activity of bacterial chitinases non-specifically. Moreover, the CBP24 has shown antifungal activity against plant pathogenic fungi Fusarium oxysporum and Rhizoctonia solani. The present study will lead us to develop a technology for environmental friendly conversion of chitin to valuable products

Pakistan Journal of Biological Sciences, Jun 15, 2001

World Journal of Microbiology & Biotechnology, Oct 1, 2005

Bioresource Technology, 1994

Saccharifying ability of thermostable cellulases on kallar grass straw at 50 and 60°C was evaluat... more Saccharifying ability of thermostable cellulases on kallar grass straw at 50 and 60°C was evaluated. Enzyme filtrate from Chaetomium thermophile saccharified 5% kallar grass straw to 69% reducing sugars (quantitatively) at 50°C. Culture filtrates from all the thermophilic fungi showed a considerable saccharification rate up to 40 h. Freeze-dried enzyme of Trichoderma reesei VTT-D-79125 (mesophile), even at higher enzyme concentration resulted in 60% reducing sugars yield (quantitatively). Glucose concentration in the hydrolysates from the fungi was in the order of C. thermophile > T. reesei > Sporotrichum thermophile > Aspergillus fumigatus > Torula thermophila > Humicola grisea > Malbranchea pulchella. At 60°C, thermostable enzymes hydrolysed kallar grass straw at a maximum rate for the initial 20 h, after which the rate essentially stopped increasing. However, at elevated temperature C. thermophile enzymes saccharified kallar grass straw up to 20 h to almost the same yield in half the time as compared to that at 50°C. The overall decline in saccharification yield (11%) of C. thermophile enzymes was significantly lower than T. reesei enzymes (34%) at 60°C.

Applied Biochemistry and Biotechnology, 2004

The effect of carbon source and its concentration, inoculum size, yeast extract concentration, ni... more The effect of carbon source and its concentration, inoculum size, yeast extract concentration, nitrogen source, pH of the fermentation medium, and fermentation temperature on β-glucosidase production by Kluyveromyces marxianus in shake-flask culture was investigated. These were the independent variables that directly regulated the specific growth and β-glucosidase production rate. The highest product yield, specific product yield, and productivity of β-glucosidase occurred in the medium (pH 5.5) inoculated with 10% (v/v) inoculum of the culture. Cellobiose (20 g/L) significantly improved β-glucosidase production measured as product yield (Y P/S) and volumetric productivity (Q P) followed by sucrose, lactose, and xylose. The highest levels of productivity (144 IU/[L•h]) of β-glucosidase occurred on cellobiose in the presence of CSL at 35°C and are significantly higher than the values reported by other researchers on almost all other organisms. The thermodynamics and kinetics of β-glucosidase production and its deactivation are also reported. The enzyme was substantially stable at 60°C and may find application in some industrial processes.

Plant Biotechnology Reports, Apr 5, 2018

Potato tubers must be cold-stored to extend their shelf life and maintain an uninterrupted supply... more Potato tubers must be cold-stored to extend their shelf life and maintain an uninterrupted supply chain for food processors. However, a side-effect of low-temperature storage is manifested in terms of cold-induced sweetening (CIS) of potato tubers, which reduces the processing quality and the commercial value of the end-products. RNA interference (RNAi) technology, whereby transgene-derived small interfering RNAs can trigger the homology-based knockdown of cognate host genes and can initiate gene silencing, has been successfully applied in crop improvement through targeted gene knockout in host plants. In the current study, transgenic potato plants (Solanum tuberosum cv. Désirée) were generated, expressing a 300 bp hairpin loop nucleotide sequence targeting the potato vacuolar invertase gene (VInv), under the constitutive Cauliflower mosaic virus 35S promoter. Tubers collected from transgenic lines showed a significant reduction in reducing sugar content after 180 days of cold storage, without showing any measurable off-target effects on plant morphology and tuberization compared to nontransformed control plants. The cold-stored tubers were further assayed for chip color, which showed a fairly light colored quality in the samples originating from RNAi lines. Together with similar effects seen in previously published experiments involving other potato varieties, the Désirée results described here establish the efficacy of using RNAi for the successful reduction of CIS in potato tubers.

Annals of Microbiology, Mar 1, 2010

The production of extracellular β-xylosidase by a newly isolated mutant derivative of Humicola la... more The production of extracellular β-xylosidase by a newly isolated mutant derivative of Humicola lanuginosa M7D on lignocellulosic substrates and xylan was maximized in solid state fermentation by adopting a search technique varying one parameter at a time. The H. lanuginosa mutant achieved maximum production of β-xylosidase (728 IU g −1 substrate, Y P/S) when grown on Vogel's medium containing xylan, followed by medium containing corncobs (669 IU g −1) supplemented with corn steep liquor (initial pH 6.5, moisture level 75%) at 45°C. Purified mutant-and parent-derived enzyme exhibited K m values of 1.8 and 2.0 mM, respectively. Both enzymes were optimally active at pH 8.5 and a temperature of 60°C. Both enzymes displayed high thermostability, with a half-life of 2.9 and 0.9 min, enthalpy of denaturation (ΔH*) of 102.1 and 110.10 kJ mol −1 , entropy of denaturation (ΔS*) of −38.5 and −4.5 J/mol K, and free energy of denaturation (ΔG*) of 115.7 and 111.7 kJ/mol at 80°C for the mutant-and parent organism-derived enzymes, respectively. The kinetic and thermodynamic properties suggest that the β-xylosidases from both strains are superior to several previously reported enzymes from other thermophilic species, and may have potential applications in various industrial fields.

Chemistry Central Journal, Oct 2, 2017

Background: The plant biomass and agro-industrial wastes show great potential for their use as at... more Background: The plant biomass and agro-industrial wastes show great potential for their use as attractive low cost substrates in biotechnological processes. Wheat straw and corn cob as hemicellulosic substrates were acid hydrolyzed and enzymatically saccharified for high xylose production. The hydrolysate was concentrated and fermented by using Saccharomyces cerevisiae and Kluyveromyces for production of xylitol. Results: Acid hydrolysis of wheat straw and corn cob in combination with enzymatic hydrolysis showed great potential for production of free sugars from these substrates. Kluyveromyces produced maximum xylitol from acid treated wheat straw residues with enzymatic saccharification. The percentage xylitol yield was 89.807 g/L and volumetric productivity of 0.019 g/L/h. Kluyveromyces also produced maximum xylitol from corn cob acid hydrolyzed liquor with xylitol yield 87.716 g/L and volumetric productivity 0.018 g/L/h. Conclusion: Plant and agro-industrial biomass can be used as a carbohydrate source for the production of xylitol and ethanol after microbial fermentation. This study revealed that wheat straw acid and enzyme hydrolyzed residue proved to be best raw material for production of xylitol with S. cerevisiae. The xylitol produced can be utilized in pharmaceuticals after purification on industrial scale as pharmaceutical purposes.

Frontiers in natural product chemistry, 2005

Journal of Biotechnology, Nov 1, 2010

Molecular Biology Reports, Mar 9, 2010

Bioresource Technology, Mar 1, 2001

Saccharomyces cerevisiae and Candida tropicalis were used separately and as co-culture for simult... more Saccharomyces cerevisiae and Candida tropicalis were used separately and as co-culture for simultaneous sacchari®cation and fermentation (SSF) of 5±20% (w/v) dry corn cobs. A maximal ethanol concentration of 27, 23, 21 g/l (w/v) from 200 g/l (w/v) dry corn cobs was obtained by S. cerevisiae, C. tropicalis and the co-culture, respectively, after 96 h of fermentation. However, theoretical yields of 82%, 71% and 63% were observed from 50 g/l dry corn cobs for the above cultures, respectively. Maximal xylitol concentration of 21, 20 and 15 g/l from 200 g/l (w/v) dry corn cobs was obtained by C. tropicalis, co-culture, and S. cerevisiae, respectively. Maximum theoretical yields of 79.0%, 77.0% and 58% were observed from 50 g/l of corn cobs, respectively. The volumetric productivities for ethanol and xylitol increased with the increase in substrate concentration, whereas, yield decreased. Glycerol and acetic acid were formed as minor by-products. S. cerevisiae and C. tropicalis resulted in better product yields (0.42 and 0.36 g/g) for ethanol and (0.52 and 0.71 g/g) for xylitol, respectively, whereas, the co-culture showed moderate level of ethanol (0.32 g/g) and almost maximal levels of xylitol (0.69 g/g).

Sahiwal cows ( n = 12 ) in early lactation were used to investigate effects of adding fibrolytic ... more Sahiwal cows ( n = 12 ) in early lactation were used to investigate effects of adding fibrolytic enzymes produced from fungus Humicola insolens on their milk production and weight gain. Cows were randomly assigned to two treatments: control and enzyme added to concentrate. The enzyme used was a blend that contained high xylanase and low cellulase activities. The crude enzyme from H. insolens was produced under inducing conditions in a 100 L bioreactor and used for feed applications. The results of present study showed that there was significant increase in weight gain of all the enzyme fed Sahiwal cows with the passage of time. The results showed an increase of 60 kg (19.33%) weight in Samosi 92/01 (Sahiwal cow) by enzyme supplementation. In other words one kg daily weight gain was observed in this cow. There was overall 286 kg (15.07%) enhancement in weight in the all enzyme fed Sahiwal cows in 60 days. In other words 0.795 kg/day weight was enhanced in each enzyme supplemented Sahiwal cow. Growing evidence indicates that treating a diet with fibrolytic enzymes improved weight gain with no marked effects on milk production.

Current Proteomics, Jul 31, 2014

Pakistan Journal of Botany, 2009

An experiment was conducted to evaluate the efficacy of multi enzyme in broiler diets containing ... more An experiment was conducted to evaluate the efficacy of multi enzyme in broiler diets containing varying levels of sunflower meal and crude fiber. Sixteen isonitrogenous experimental diets were prepared using 0, 5, 10 and 15% SFM and 4, 5, 6 and 7% CF, respectively with and without enzyme supplementation and fed to 480 day old broiler chicks. Data on feed consumption, weight gain, feed conversion ratio and dressing percentage was collected. Results showed significant differences (p<0.05) among different experimental diets for weight gain and feed conversion. The highest weight gain was observed in chicks fed on diet containing 10% SFM and 6% CF with Grindazym while the lowest weight gain was obtained on diet having 10% SFM and 6% CF without enzyme supplementation. Diet containing 15% SFM and 7% CF with NIBGE enzyme @1% of 2.5 Fold was found best on the other hand diet containing 5% SFM and 5% CF without enzyme supplementation had poorest feed conversion among all the experimental diets. Feed intake during the experimental period was not influenced (p>0.05) either by dietary SFM and CF level or enzyme supplementation. However, maximum feed was consumed by birds fed diet containing 5% SFM and 5% CF without enzyme supplementation. While the minimum feed intake was observed on diet formulated with 15% SFM and 7% CF without addition of any enzyme. Dressing percentage was calculated as carcass weight excluding skin including internal organs viz., heart, liver, gizzard and kidneys of the birds. No differences (p>0.05) were observed for dressing percentages on different experimental diets. Results from this experiment suggest that enzyme supplementation can improve nutritive value of high fiber broiler diets. Broiler chicks can grow faster and more efficiently on a diet containing fiber degrading enzymes than on a diet without enzymes.