2024-03-29T04:08:05Z
https://www.biofueljournal.com/?_action=export&rf=summon&issue=8773
Biofuel Research Journal
BRJ
2018
5
3
Editorial Board
2018
09
01
https://www.biofueljournal.com/article_68398_9d3bfda4aa2d53ac480b11e015544826.pdf
Biofuel Research Journal
BRJ
2018
5
3
Adapting the yeast consolidated bioprocessing paradigm for biorefineries
Riaan
den Haan
Despite decades long development, no natural or engineered organism has been isolated that can produce commodity products at the rates and yields required by industry via direct microbial conversion. However, new genomic editing tools and systems level knowledge of metabolism provides opportunities to develop yeast strains for second-generation biorefineries.
2018
09
01
827
828
https://www.biofueljournal.com/article_68399_813e191cb43a00de54ff328a1cf93af5.pdf
Biofuel Research Journal
BRJ
2018
5
3
Fueling the future; plant genetic engineering for sustainable biodiesel production
Gholamreza
Salehi Jouzani
Reza
Sharafi
Saeed
Soheilivand
Biodiesel has huge potentials as a green and technologically feasible alternative to fossil diesel. However, biodiesel production from edible oil crops has been widely criticized while nonedible oil plants are associated with some serious disadvantages, such as high cost, low oil yield, and unsuitable oil composition. The next generation sequencing (NGS), omics technologies, and genetic engineering have opened new paths toward achieving high performance-oil plants varieties for commercial biodiesel production. The intent of the present review paper is to review and critically discuss the recent genetic and metabolic engineering strategies developed to overcome the shortcoming faced in nonedible plants, including Jatropha curcas and Camelina sativa, as emerging platforms for biodiesel production. These strategies have been looked into three different categories. Through the first strategy aimed at enhancing oil content, the key genes involved in triacylglycerols (TAGs) biosynthesis pathway (e.g., diacylglycerol acyltransferase (DGAT), acetyl-CoA carboxylase (ACCase), and glycerol‐3‐phosphate dehydrogenase (GPD1)), genes affecting seed size and plant growth (e.g., transcription factors (WRI1), auxin response factor 19 (ARF19), leafy cotyledon1 (LEC1), purple acid phosphatase 2 (PAP2), G-protein c subunit 3 (AGG3), and flowering locus T (FT)), as well as genes involved in TAGs degradation (e.g., sugar-dependent protein 1 triacylglycerol lipase (SDP1)) have been deliberated. While through the second strategy targeting enhanced oil composition, suppression of the genes involved in the biosynthesis of linoleic acids (e.g., fatty acid desaturase (FAD2), fatty acid elongase (FAE1), acyl-ACP thioesterase (FATB), and ketoacyl-ACP synthase II (KASII)), suppression of the genes encoding toxic metabolites (curcin precursor and casbene synthase (JcCASA)), and finally, engineering the genes responsible for the production of unusual TAGs (e.g., Acetyl-TAGs and hydroxylated fatty acids (HFA)) have been debated. In addition to those, enhancing tolerance to biotic (pest and disease) and abiotic (drought, salinity, freezing, and heavy metals) stresses as another important genetic engineering strategy to facilitate the cultivation of nonedible oil plants under conditions unsuitable for food crops has been addressed. Finally, the challenges faced prior to successful commercialization of the resultant GM oil plants such have been presented.
Biodiesel
Genetic engineering
Nonedible oil plants
Oil content
Oil composition
Biotic and abiotic stress tolerance
2018
09
01
829
845
https://www.biofueljournal.com/article_68377_45b1b0a7700f9c993de5b4c067e1ea80.pdf
Biofuel Research Journal
BRJ
2018
5
3
Enzymatic hydrolysis of biologically pretreated sorghum husk for bioethanol production
Pankajkumar R.
Waghmare
Rahul V.
Khandare
Byong-Hun
Jeon
Sanjay P.
Govindwar
Biological pretreatment of lignocellulosic biomass is considered to be energy-efficient and cost-effective. In the present study, sorghum husk was biologically pretreated with a white-rot fungus Phanerochaete chrysosporium (MTCC 4955) under submerged static condition. Ligninolytic enzymes like lignin peroxidase (0.843 U/mL) and manganese peroxidase (0.389 U/mL) played an important role in the biological pretreatment of sorghum husk. Activities of different hydrolytic enzymes such as endoglucanase (57.25 U/mL), exoglucanase (4.76 U/mL), filter paperase (0.580 U/mL), glucoamylase (153.38 U/mL), and xylanase (88.14 U/mL) during biological pretreatment of sorghum husk by P. chrysosporium were evaluated. Enzymatic hydrolysis of untreated sorghum husk and biologically pretreated sorghum husk produced 20.07 and 103.0 mg/g reducing sugars, respectively. This result showed a significant increase in reducing sugar production in the biologically pretreated sorghum husk as compared to its untreated counterpart. Biologically pretreated sorghum husk hydrolysate was further fermented for 48 h using Saccharomyces cerevisiae (KCTC 7296), Pachysolen tannophilus (MTCC 1077), and their co-culture resulting in ethanol yields of 2.113, 1.095, and 2.348%, respectively. The surface characteristics of the substrate were evaluated after the delignification and hydrolysis, using FTIR, XRD, and SEM, confirming the effectiveness of the biological pretreatment process.
Sorghum husk
Phanerochaete chrysosporium
Delignification
Biological pretreatment
Enzymatic hydrolysis
Ethanol production
2018
09
01
846
853
https://www.biofueljournal.com/article_68378_3e65242df039dc49815df6fdf811c0b0.pdf
Biofuel Research Journal
BRJ
2018
5
3
Comparative investigation of the effect of hemispherical and toroidal piston bowl geometries on diesel engine combustion characteristics
Manjunath
Channappagoudra
K.
Ramesh
G.
Manavendra
Diesel engine parameters are in general more compatible with operating on neat diesel than biodiesel and its blends. Therefore, optimizing operating conditions as well as piston bowl geometry to achieve a better performance with biodiesel in conventional diesel engines is highly essential. In the present study, hemispherical piston bowl geometry (HPBG) of existing diesel engine was modified into toroidal piston bowl geometry (TPBG) to evaluate the performance of a diesel engine running on a 20% blend of dairy scum oil biodiesel (B20). The experimental results revealed increased brake thermal efficiency and heat release rate by 5.5% and 17.24%, respectively, while brake specific fuel consumption, HC emission, and CO emission were decreased by 8.75%, 15%, and 14.47%, respectively, in response to the engine modification applied. Such improvements using the TPBG could be attributed to improved fuel atomization, reduction of fuel droplet size, increased cylinder temperature, enhanced squish-swirl, and turbulence kinetic energy during combustion. The findings of the present study could pave the way for the fabrication of diesel engines, which are more efficiently compatible with biodiesel and its blends.
Diesel engine
Piston bowl geometry
Nozzle hole
Dairy scum oil biodiesel
Combustion characteristics
2018
09
01
854
862
https://www.biofueljournal.com/article_68380_815ff204724b0827ab00432dfd9fbb46.pdf
Biofuel Research Journal
BRJ
2018
5
3
Experimental investigation of the combustion characteristics of Mahua oil biodiesel-diesel blend using a DI diesel engine modified with EGR and nozzle hole orifice diameter
M.
Vijay Kumar
A.
Veeresh Babu
P.
Ravi Kumar
S.
Sudhakara Reddy
Engine modification through reducing nozzle hole diameter (NHD) (i.e., from the base value of 0.28 to the modified value of 0.20 mm) has been shown as an effective strategy in improving engine performance, combustion, and emission parameters. However, it has also led to substantial increases in NOx emission as a major shortcoming. In light of that, the present study was aimed at overcoming this challenge through the application of a partially-cooled exhaust gas recirculation (EGR) system. More specifically, Mahua oil biodiesel-diesel blend (B20) and neat diesel were tested on a modified single cylinder diesel engine under five different engine loads (i.e., 2.46, 4.92, 7.38, 9.84, and 12.3 kg) and in the presence of varying EGR rates (i.e., 10, 20, and 30%). The results obtained revealed that the performance, combustion, and emission characteristics of the modified engine (3-hole nozzle with an orifice diameter of 0.20 mm) were improved for both neat diesel and B20 except in the case of NOx, in comparison with those of the conventional diesel engine (3-hole nozzle with an orifice diameter of 0.28 mm). The considerable increases in NOx emissions caused by the smaller orifice NHD could be successfully compensated for through the implementation of the partially-cooled EGR. Overall and based on the findings of the present study, the proposed engine modification in the presence of partially-cooled EGR rate of 10% could be recommended as efficient combustion conditions for 20% blend of Mahua oil biodiesel and diesel. However, further increments in the EGR rate and in particular at higher loads, adversely affected the performance and emission characteristics of the modified engine due to the recirculation of high amounts of unburnt soot, CO2, H2O, as well as of O2 deficiency.
Diesel engine modification
Injector nozzle hole diameter
Biodiesel
Combustion characteristics
EGR
NOx reduction
2018
09
01
863
871
https://www.biofueljournal.com/article_68382_c971a717f39407063fc953206191eeda.pdf