Theoretical Considerations for Economics of Second- and Third- Generation Biofuels

Ground is being prepared all over the world for installation of biofuel plants which can govern the sustainable supply of cleaner fuels at affordable prices and predictable amounts. At the dawn of this century biofuels identified low cost feedstocks, their diverse pretreatments, different methods of saccharifications and fermentations and those for cultivation of biodiesel yielding organisms. Bioalcohols, biohydrogen and biogas represent the biofuels which are derived from microbial work on the biowaste-resources. Extensions in this sector have focused the solar energy captured by the microalgae from which oils can be extracted for biodiesel. Undoubtedly, all forms of available energies on this planet earth had/have been derived, directly or indirectly, from the solar inputs. In this chapter pivotal role of solar insolation will be discussed albeit for regeneration as well as processing of lignocellulosic biomass for obtaining biofuels. Conclusively, biofuels’ sustainable supplies, role of solar energy has been dreamt at various steps of the process; from the collection of biowaste resources through steps of pretreatment, saccharification / fermentation and purification of the product. This chapter discusses the subject matter into two major sub-headings: 1) Biofuels from lignocellulosic / food industrial wastes and 2) Cultivation of microbes for biodiesel

Psychrophilic Microbial Enzymes Implications in Coming Biotechnological Processes

Psychrophilic microorganisms produce a variety of cold-active enzymes which are used as production accelerators at commercial level to cope increasing demands necessitating low temperature conditions. The psychrophilic enzymes are frequently employed in food processing, textile, detergents, feed stocks, bioremediation, cosmetics, paper and pharmaceutical industries. But being extermophilic in nature, psychrophiles have certain pH, ionic strength and temperature limitation. To overcome such issues, their molecular biology and beneficial genetic engineering approaches are current goals of researchers. In this regard, many successful studies have accomplished importance of cold-active enzymes at industrial level. This review summarizes applications of potential psychrozymes

Isolation of Acidophilic Lactic Acid Bacteria Antagonistic to Microbial Contaminants

Abstract.-Four species of lactic acid bacteria viz. L. bulgaricus, L. casei, L. acidophilus and L. salivarius were isolated from a local yogurt sample. The bacterium L. salivarius showed maximum growth at 37°C with initial pH 6. L. bulgaricus and L. acidophilus also grew best at 37°C but with initial pH 4.The bacterium L. casei showed maximum growth at 25°C at pH 5. All the four bacteria formed smooth textured and white yogurt at 2% inoculum. L. acidophilus tolerated acid upto 1 pH . However, L. bulgaricus and L. salivarius showed more resistance to acid when cultured in yogurt as compared to their cultivations in the selective medium. These lactic acid bacteria demonstrated antimicrobial activity against different isolates of E. coli, Staphylococcus sp., Salmonella sp. and yeasts. The L. acidophilus was found to be the most potent antagonistic microbe against E. coli, while the isolate L. bulgaricus expressed vivid antifungal activity. Acid tolerance, yogurt fermentation and bacterial and fungal antagonistic characteristics of these bacterial isolates render them good candidates for their consideration as probiotics

Potential of Cellulosic Ethanol to Overcome Energy Crisis in Pakistan

Liquid biofuel industry in Pakistan may become a promising source for saving our foreign exchange and environment. Currently, bioethanol production is dependent on cane molasses, a product of sugar industry. Harnessing of more bioethanol from lignocellulosic waste crop residue has potential to respond to the fuel scarcity. Lignocellulose exists in nature as a polymer and serves as the largest sink for fixed global carbon and could be used both as a carbon source for microbial growth-assisted bioethanol production and for fabricating enzymes for more energetic simultaneous production to represent an important segment of the renewable energy sector. An exciting aspect of this research is the development of new biorefining techniques that facilitate the extraction of sugar-derived biofuel by processing of waste crop residues by employing novel nature inspired lignolytic enzyme. Further research will explore more avenues for stabilization of system in terms of process parameters for optimum bioethanol yield from enzymatically hydrolyzed lignin waste streams. The chapter can be considered as an anticipatory work and exploration of new dimensions for promotion of nature-inspired enzyme-assisted lignocellulose-based bioethanol production industry, which maximizes sustainable development opportunities especially in energy sector

Metal bioaccumulation levels in different organs of three edible fish species from the river Ravi, Pakistan

Metals bioaccumulation in five organs of Cirrhinus  mrigala, Labeo  rohita and Catla catla captured from three industrial and sewage polluted downstream sites (Shahdera = B, Sunder = C and Balloki = D) were compared with a non-industrial upstream site (Siphon = A) during high (post monsoon) and low (winter) flow seasons of river Ravi. Mean concentrations of metals were significantly higher in low flow than the high flow season. Pattern of metal accumulation in the studied organs was: Zn > Fe > Mn > Cu > Cr > Pb > Ni > Hg > Cd. Kidneys showed mostly greater metal bioaccumulation than intestines, hearts, eyes and gills. Among fish species, the highest concentrations (µg/g dry weight) of Cr (3.77), Zn (56.22), Mn (8.95), Ni (1.70) and Hg (1.60) and lowest of Pb (2.53) were detected in C. mrigala whereas Cu (7.19), Fe (62.11) and Pb (2.64) appeared higher while Zn (52.69), Mn (7.82) and Ni (1.41) with lowest concentrations in C. catla. In contrast, lower concentrations of Cd (0.15), Cr (3.16), Cu (7.06) and Fe (54.18) were recorded in L. rohita. Accumulation of the metals was significantly different in organs among the different sampling sites. Based on metals accumulation pattern, second downstream site (Sunder) identified as the most polluted site due to untreated industrial and municipal discharges. Measured elevated levels of metals concentrations in fish organs indicated potential health risks for the fish and the food chain

Optimization of sulphuric acid pre-treatment of Acacia saw dust through box-bhenken design for cellulase production by B. Subtilis

Background: Cellulases are enzymes which are capable of degrading lignocellulosic biomass. The current study is centred on optimization of dilute sulphuric acid pre-treatment of Acacia saw dust for maximizing cellulase production (CMCase and FPase). Hydrolysis or saccharification of lignocellulosic biomass is brought about by cellulases and the sugar thus released can be used for further bioethanol production.Methods: Box- Bhenken design (BBD) was employed for optimization of pre-treatment conditions for Acacia saw dust. Three variables i.e. sulphuric acid concentration (0.6%, 0.8% and 1.0% v/v), substrate concentration (5%,10% and15%)  and reaction time (4h,6h and 8h) was optimized. The pre-treated saw dust was used in the study as a substrate for producing cellulase enzyme through submerged fermentation by Bacillus subtilis (K-18).Results: An optimum conditions i.e. (0.8% H2SO4 conc., 15% substrate conc. and 4h of reaction time) yielded highest filter paper activity (1.3617 IU/ml/min) and CMCase activity (0.7783 IU/ml/min). The suggested model was significant as revealed by F-value, coefficient of determination (R2) andP-value.Conclusion: Results concluded that pre-treated substrate (Acacia sawdust) significantly increased cellulase production as compared to untreated substrate that could be utilized for further biofuel production

Original Article Solid state fermentation of fish feed with amylase producing bacteria

Abstract A formulated fish feed was fermented with amylase producing Bacillus cereus (Sn-1 and Sn-3) and Proteus mirabilisis -Sn-2 employing solid state fermentation (SSF) at their corresponding optimized growth conditions. SSF of the fish feed indicated significant increase and decreases in glucose and starch contents within seven days, respectively. Significant elevations also occurred in protein levels as compared to the corresponding values of non fermented control feed. The protein levels increased up to 42.27% by B. cereus-Sn-1 after 24 hours, 63.16% by P. mirabilis-Sn-2 after 168 hours and 47.47% by B. cereus-Sn-3 after 168 hours of incubations. These bacterial isolates caused the nutritional increments with 10% inocula and 70% moisture contents. The C.F.U./g of fermented feeds paralleled, in general, the feed nutritional enrichment. These results are reminiscent to design commercial level solid state fermentation facilities for developing the aquafeed industry in this country

Utjecaj sastava podloge na komercijalnu proizvodnju alkalne proteaze s pomoću soja Bacillus licheniformis N-2

Protease production by alkalophilic B. licheniformis N-2 was investigated in 50 mL of the growth medium consisting of (in g/L): glucose 10.0, soybean meal 10.0, K2HPO4 3.0, MgSO4·7H2O 0.5, NaCl 0.5 and CaCl2·2H2O 0.5 at pH=10. Different carbon and nitrogen sources in the form of fine powder of organic, inorganic and defatted meals were studied to select the suitable substrate for alkaline protease production. The highest level of alkaline protease (677.64 U/mL) was obtained in the medium containing glucose followed by soluble starch and wheat bran. Among various nitrogen sources, defatted soybean meal was found to be the best inducer of alkaline protease, while inorganic nitrogen sources in the form of ammonium salts repressed the enzyme activity up to 96 %. Thermostability studies showed that the enzyme in the presence of 10 mM Ca2+ ions retained its residual activity up to 80 % even after incubation at 40 °C for 12 h. The enzyme was found stable over a broad range of pH (8–11) and lost 52 % of its residual activity at pH=12. After the treatment with Tween 20, Tween 45, Tween 65, Triton X-405, H2O2 and sodium perborate, each at 1.0 % concentration, the enzyme showed residual activity of 105, 82, 116, 109, 135 and 126 %, respectively. The application of alkaline protease for removal of blood stains from cotton fabric also indicates its potential use in detergent formulations.U radu je istražena proizvodnja proteaze s pomoću alkalofilnog soja bakterije Bacillus licheniformis N-2 u 50 mL podloge sastava (u g/L): glukoza 10,0; sojina sačma 10,0; K2HPO4 3,0; MgSO4·7H2O 0,5; NaCl 0,5 i CaCl2·2H2O 0,5; pH=10. Dodatkom raznih izvora ugljika i dušika u obliku finih praškastih organskih, anorganskih i nemasnih hranjiva, odabran je prikladan supstrat za proizvodnju alkalne proteaze. Najviše alkalne proteaze (677,64 U/mL) proizvedeno je u podlozi s glukozom, a nešto manje sa škrobom i mekinjama. Utvrđeno je da je nemasna sojina sačma najbolji izvor dušika za proizvodnju alkalne proteaze, dok su amonijeve soli smanjile aktivnost enzima i do 96 %. Ispitivanje termostabilnosti enzima pokazalo je da on, u prisutnosti Ca2+ iona u koncentraciji od 10 mM, zadržava čak do 80 % aktivnosti i nakon inkubacije pri 40 °C tijekom 12 sati. Enzim je bio stabilan u području pH-vrijednosti od 8 do 11, a pri pH=12 izgubio je 52 % rezidualne aktivnosti. Nakon obrade različitim 1,0 %-tnim otopinama izmjerena je ova rezidualna aktivnost enzima: 105 % s Tween 20, 82 % s Tween 45, 116 % s Tween 65, 109 % s Triton X-405, 135 % s H2O2 i 126 % s natrijevim perboratom. Alkalna se proteaza može primijeniti u proizvodnji detergenata za uklanjanje mrlja od krvi pri pranju tkanina