Bioenergy production in Pakistan: Potential, progress, and prospect.

Pakistan is a developing country with a rapidly growing population. It is currently facing serious economic and energy challenges. Pakistan's energy demand is increasing by the day, and it now stands at 84 MTOE.

Bioenergy from dairy manure: technologies, challenges and opportunities.

Dairy manure (DM) is a kind of cheap cellulosic biomass resource which includes lignocellulose and mineral nutrients. Random stacks not only leads damage to the environment, but also results in waste of natural resources. The traditional ways to use DM include returning it to the soil or acting as a fertilizer, which could reduce environmental pollution to some extent.

Metabolic engineering of Zymomonas moblis for ethylene production from straw hydrolysate.

Biological ethylene production is a promising sustainable alternative approach for fossil-based ethylene production. The high glucose utilization of Z. mobilis makes it as a promising bioethylene producer.

Biochar-mediated enhanced ethanol fermentation (BMEEF) in under furfural and acetic acid stress.

Background: Pretreatment of lignocellulosic biomass generates different types of inhibitors (e.g., furfural and acetic acid), which could remarkably inhibit subsequent ethanol fermentation.

Replacing process water and nitrogen sources with biogas slurry during cellulosic ethanol production.

Background: Environmental issues, such as the fossil energy crisis, have resulted in increased public attention to use bioethanol as an alternative renewable energy. For ethanol production, water and nutrient consumption has become increasingly important factors being considered by the bioethanol industry as reducing the consumption of these resources would decrease the overall cost of ethanol production. Biogas slurry contains not only large amounts of wastewater, but also the nutrients required for microbial growth, e.

The Enrichment of Microbial Community for Accumulating Polyhydroxyalkanoates Using Propionate-Rich Waste.

Polyhydroxyalkanoates (PHAs) are promising alternatives to plastics since they have similar properties to polyolefin but are biodegradable and biocompatible. Recently, the conversion of propionate wastewater to PHAs by undefined mixed microbial cultures becomes attractive. However, how microbial community changes remains unclear during the enrichment step, which is critical for a robust PHA-producing system.

Engineered Zymomonas mobilis for salt tolerance using EZ-Tn5-based transposon insertion mutagenesis system.

Background: The cell growth and ethanol yield of Zymomonas mobilis may be detrimentally affected by salt stress frequently present in some biomass-based fermentation systems, leading to a decrease in the rate of sugar conversion to ethanol or other bioproducts. To address this problem, improving the salt tolerance of Z. mobilis is a desirable way.

Adaption of microbial community during the start-up stage of a thermophilic anaerobic digester treating food waste.

A successful start-up enables acceleration of anaerobic digestion (AD) into steady state. The microbial community influences the AD performance during the start-up. To investigate how microbial communities changed during the start-up, microbial dynamics was analyzed via high-throughput sequencing in this study.

Paenibacillus salinicaeni sp. nov., isolated from saline silt sample.

A novel facultatively anaerobic bacterium, designated strain LAM0A28(T), was isolated from a saline silt sample collected from the Chinese Sea of Death located in Suining city, Sichuan province, China. Cells of strain LAM0A28(T) were observed to be Gram-stain positive, motile, endospore-forming and straight-rod shaped. Strain LAM0A28(T) was found to be able to grow at 15-45 °C (optimum: 30-35 °C), pH 5.

Complete genome sequence of strain Lentibacillus amyloliquefaciens LAM0015(T) isolated from saline sediment.

The type strain Lentibacillus amyloliquefaciens LAM0015(T) with considerably highly NaCl tolerance is a member of halophiles. Here we report its genome sequence, the first to publish complete genome sequence of the Lentibacillus genus. It contains 3,858,520bp with an average GC content of 42.

Lentibacillus amyloliquefaciens sp. nov., a halophilic bacterium isolated from saline sediment sample.

A Gram-stain positive, non-motile, non-sporogenous, aerobic, rod-shaped and halophilic bacterium, designated LAM0015(T), was isolated from a saline sediment sample collected from Yantai City in China. The isolate was found to be able to grow at NaCl concentrations of 5-25 % (w/v) (optimum: 7-12 %), 15-45 °C (optimum: 35 °C) and pH 5.0-9.

Adaptive laboratory evolution of ethanologenic Zymomonas mobilis strain tolerant to furfural and acetic acid inhibitors.

Furfural and acetic acid from lignocellulosic hydrolysates are the prevalent inhibitors to Zymomonas mobilis during cellulosic ethanol production. Developing a strain tolerant to furfural or acetic acid inhibitors is difficul by using rational engineering strategies due to poor understanding of their underlying molecular mechanisms. In this study, strategy of adaptive laboratory evolution (ALE) was used for development of a furfural and acetic acid-tolerant strain.

Paenibacillus vini sp. nov., isolated from alcohol fermentation pit mud in Sichuan Province, China.

A novel facultatively anaerobic bacterial strain, designated LAM0504(T), was isolated from a pit mud of Luzhou flavour liquor alcohol fermentation in Sichuan Province, China. Cells of strain LAM0504(T) were observed to be Gram-stain negative, spore-forming, rod shaped and motile by means of peritrichous flagella. Strain LAM0504(T) was found to be able to grow at 20-48 °C (optimum: 30 °C), pH 5.

Improving furfural tolerance of Zymomonas mobilis by rewiring a sigma factor RpoD protein.

Furfural from lignocellulosic hydrolysates is the key inhibitor for bio-ethanol fermentation. In this study, we report a strategy of improving the furfural tolerance in Zymomonas mobilis on the transcriptional level by engineering its global transcription sigma factor (σ(70), RpoD) protein. Three furfural tolerance RpoD mutants (ZM4-MF1, ZM4-MF2, and ZM4-MF3) were identified from error-prone PCR libraries.

Transcriptional analysis of adaptation to high glucose concentrations in Zymomonas mobilis.

The ethanologenic bacterium Zymomonas mobilis is usually tolerant to high concentrations of glucose. The addition of sorbitol decreases the lag phase and increases ethanol yield and productivity of the bacteria in high glucose concentrations. The molecular mechanisms of adaptation to high glucose concentrations and the effect of sorbitol are still unclear.

Bamboo: a new source of carbohydrate for biorefinery.

Bamboo is perennial woody grass, which distributed widely in the world and belonged to the Gramineae family and Bambuseae subfamily. It may be consider as a candidate lignocellulosic substrate for bio-ethanol production for its environmental benefits and higher annual biomass yield. The conversion of bamboo into bio-ethanol, bio-methane, natural food, flavonoids, and functional xylo-oligosaccharides production were reviewed in this paper.

Construction of a novel secretion expression system guided by native signal peptide of PhoD in Zymomonas mobilis.

In the current study, three native signal peptides (SPs) from PhoC, PhoD, and ZMO0331were investigated and compared to construct novel secretion expression systems in Zymomonas mobilis. The secretion expression of target protein, α-amylase from Bacillus amyloliquefaciens (BAA), guided by PhoD's SP resulted in more hydrolysis of starch than that by the other two SPs. Extracellular and intracellular α-amylase activities of the strain containing PhoD's SP were also higher than the other two strains containing PhoC or ZMO0331's SP.

Zymomonas mobilis: a novel platform for future biorefineries.

Biosynthesis of liquid fuels and biomass-based building block chemicals from microorganisms have been regarded as a competitive alternative route to traditional. Zymomonas mobilis possesses a number of desirable characteristics for its special Entner-Doudoroff pathway, which makes it an ideal platform for both metabolic engineering and commercial-scale production of desirable bio-products as the same as Escherichia coli and Saccharomyces cerevisiae based on consideration of future biomass biorefinery. Z.

Transcriptome profiling of Zymomonas mobilis under ethanol stress.

Background: High tolerance to ethanol is a desirable characteristics for ethanologenic strains used in industrial ethanol fermentation. A deeper understanding of the molecular mechanisms underlying ethanologenic strains tolerance of ethanol stress may guide the design of rational strategies to increase process performance in industrial alcoholic production. Many extensive studies have been performed in Saccharomyces cerevisiae and Escherichia coli.

Transcriptome profiling of Zymomonas mobilis under furfural stress.

Furfural from lignocellulosic hydrolysates is the prevalent inhibitor to microorganisms during cellulosic ethanol production, but the molecular mechanisms of tolerance to this inhibitor in Zymomonas mobilis are still unclear. In this study, genome-wide transcriptional responses to furfural were investigated in Z. mobilis using microarray analysis.

[Site-directed mutagenesis and function analysis of glgC gene from Escherichia coli.].

Using genomic DNA of Escherichia coli JM109 as a template, glgC gene was amplified by polymerase chain reaction (PCR). The full coding sequence of this gene is 1296 bp. To get 3 mutants that amino acids changed: P295S (V121A, M151I, V334D), G336D and P295S/G336D (K109R) by recombinant PCR, respectively named 295+3, 336 and 295/336+1.

Construction of a novel cell-surface display system for heterologous gene expression in Escherichia coli by using an outer membrane protein of Zymomonas mobilis as anchor motif.

A novel bacterial cell-surface display system was developed in Escherichia coli using omp1, a hypothetical outer membrane protein of Zymomonas mobilis. By using this system, we successfully expressed beta-amylase gene of sweet potato in E. coli.