Scielo RSS <![CDATA[Electronic Journal of Biotechnology]]> vol. 18 num. 1 lang. es <![CDATA[SciELO Logo]]> <![CDATA[<strong>Polymorphism of three milk protein genes in Mexican Jersey cattle</strong>]]> The objective was to estimate the allelic and genotypic frequencies, genetic diversity and polymorphic information content for the β-casein, κ-casein and β-lactoglobulin genes. Blood and frozen semen samples were collected from 453 Jersey individuals registered by the Mexican Jersey Cattle Association. Twenty eight breed specific SNP primers for whole genes were used. The B allele of κ-casein had higher frequency (0.69) than the A (0.26) and E (0.05). For β-lactoglobulin, the highest frequency was for B (0.72), followed by A and C alleles (0.26 and 0.02, respectively). The β-casein allele with the highest frequency was A² (0.71), followed by A¹ (0.19), A³ (0.05), B (0.04) and C (0.01). The average genetic diversity (He) was 0.53. The average locus effective allele number was 1.79. These results indicate a high allelic diversity for κ-caseín, β-casein and β-lactoglobulin that could be included in breeding programs in the population studied, aimed to improve the milk quality traits of economic importance. <![CDATA[<strong>Characterization and evaluation of coconut aroma produced by </strong><em><b>Trichoderma viride</b></em><strong> EMCC-107 in solid state fermentation on sugarcane bagasse</strong>]]> Background Sugarcane bagasse was shown to be an adequate substrate for the growth and aroma production by Trichoderma species. In the present work the ability of Trichoderma viride EMCC-107 to produce high yield of coconut aroma in solid state fermentation (SSF) by using sugarcane bagasse as solid substrate was evaluated. The produced aroma was characterized. Results Total carbohydrates comprised the highest content (43.9% w/w) compared with the other constituents in sugarcane bagasse. The sensory and gas chromatography-mass spectrometric (GC-MS) analysis revealed that the highest odor intensity and maximum yield of volatiles were perceived at the 5th d of induction period. The unsaturated lactone, 6-pentyl-α-pyrone (6-PP), was the major identified volatile compound. Saturated lactones, δ-octalactone, γ-nonalactone, γ-undecalactone, γ-dodecalactone and δ-dodecalactone, were also identified in the coconut aroma produced during the induction period (12 d). A quite correlation was found between the composition and odor profile of the produced aroma. The effect of varying the concentration of sugarcane bagasse on 6-PP production and biomass growth was evaluated. The results revealed high 6-PP production at 4.5 g sugarcane bagasse whereas the biomass showed significant (P < 0.05) increase by increasing the concentration of sugarcane bagasse. Conclusion The concentration of 6-PP, the most contribution of coconut aroma, produced in present study (3.62 mg/g DM) was higher than that reported in previous studies conducted under the same fermentation conditions. The significant increase in biomass with increasing the concentration of sugarcane bagasse may be attributed to the increase in sugar content that acts as carbon and energy source. <![CDATA[<strong>Potential of giant reed (</strong><em><b>Arundo donax</b></em><strong> L.) for second generation ethanol production</strong>]]> Background The production of second generation ethanol from lignocellulosic biomasses that have not had their potential fully explored as feedstock is of great importance. Arundo donax is one these biomasses. It is a promising grassy plant to be used as a renewable resource for the production of fuels and chemicals, because of its fast growth rate, ability to grow in different soil types and climatic conditions. The present study evaluated its use as feedstock for the production of second generation ethanol. Results Initially its chemical characterization was carried out, and a protocol for fractioning the biomass through diluted acid pretreatment followed by alkaline pretreatment was developed, providing a solid fraction which was undergone to enzymatic hydrolysis reaching 42 g/L of glucose, obtained in 30 h of enzymatic hydrolysis. This partially delignified material was subjected to a simultaneous saccharification and fermentation (SSF) process, resulting in an ethanol concentration of 39 g/L at 70 h. Conclusions The fermentability of the pretreated biomass was performed successfully through the conception of simultaneous saccharification and fermentation resulting in approximately 75 L of ethanol per ton of cellulose. <![CDATA[<strong>Fibrinolytic protease production by new </strong><em><b>Streptomyces</b></em><strong> sp</strong>: <strong>DPUA 1576 from Amazon lichens</strong>]]> Background Streptomyces sp. DPUA 1576 from Amazon lichens was studied to protease and fibrinolytic production. A 2² factorial experimental design was applied to optimize its protease enzyme production using two independent variables, namely soybean flour and glucose concentrations. Results The optimal conditions to obtain high protease production (83.42 U/mL) were 1.26% soybean flour and 1.23% glucose concentration. A polynomial model was fitted to correlate the relationship between the two variables and protease activity. In relation to fibrinolytic activity, the highest activity of 706.5 mm² was obtained at 1.7% soybean flour and 1.0% glucose concentration, which was 33% higher than plasmin. Fibrinolytic production was not optimized in the studied conditions. Conclusions These results show that the optimization of the culture medium can enhance protease production, thus becoming a good process for further research. In addition, Streptomyces sp. DPUA 1576, isolated from Amazon lichens, might be a potential strain for fibrinolytic protease production. <![CDATA[<strong>Utilization of coconut oil mill waste as a substrate for optimized lipase production, oil biodegradation and enzyme purification studies in </strong><em><b>Staphylococcus pasteuri</b></em>]]> Background Oil and grease laden wastewaters pose hindrance to the treatment units and further threaten the receiving water bodies. Lipase-producing microbial strains are increasingly being exploited for the remediation of such effluents. Results When bacterial strains isolated from oil mill effluent were screened for their lipolytic activity, two isolates, COM-4A and COM-6B showed significant extracellular lipase activity. They were identified to be Staphylococcus pasteuri and Bacillus subtilis, respectively. S. pasteuri COM-4A was cultivated in nutrient media based on coconut oil mill waste (CMW), in which it showed good growth at concentrations up to 20 g/L. While growing in such media, it was capable of producing lipase and other important extracellular hydrolytic enzymes. Furthermore, the isolate was able to effectively biodegrade the CMW supplemented in the medium. Applying the Box Behnken Design of Response Surface Methodology, lead to a 1.4-fold increase in both lipase production and oil removal by the isolate. The lipase was purified 9.02-fold and the molecular weight of the monomeric enzyme was deduced to be around 56 kDa. Characterization of the enzyme revealed it to be alkaliphilic and moderately thermophilic in nature, with pH and temperature optima of 9.0 and 50°C, respectively. The enzyme was also quite stable in the presence of water-miscible organic solvents. Conclusion Hence, the COM-4A lipase could be considered to be suitable for a variety of industrial applications such as in detergent formulations and in biodiesel production as well, apart from the possibility of applying it for bioremediation of fat and oil contaminants. <![CDATA[<strong>A comparative proteomic study of white and black glutinous rice leaves</strong>]]> Background Black glutinous rice contains remarkable levels of anthocyanins, which possess anti-oxidative properties and thus have health benefits. The accumulation of anthocyanins in grains of thirty black glutinous rice varieties was measured, and the results revealed that the accumulated anthocyanin content ranged from 0.262 to 2.539 mg/g. Black glutinous rice Br no. 19 was selected, and its leaf protein expression profile was compared with that of white glutinous rice RD 6 using 2D-PAGE, and the protein spots were then directly analyzed after proteolysis by LC-MS/MS. Results The proteins from the leaves of the two rice varieties were separated using 2D-PAGE and silver stained, and the spots were analyzed using Image Master 2D Platinum version 5 software. The results showed that the protein profiles of these two rice cultivars were different, with at least six protein spots that were detected only in Br no. 19. In addition, seven protein spots accumulated at higher levels in Br no. 19 than in RD 6. Conclusion The protein spot S1 (AP005098.4) is homologous to the Rc protein. Our results suggest that some of the proteins enriched in Br no. 19 may be involved in anthocyanin synthesis in the black glutinous rice. <![CDATA[<strong>Development and significance of RAPD-SCAR markers for the identification of </strong><em><b>Litchi chinensis</b></em><strong> Sonn</strong>: <strong>by improved RAPD amplification and molecular cloning</strong>]]> Background Analysis of genetic diversity is important for the authentication of a species. Litchi (Litchi chinensis Sonn.) is a subtropical evergreen tree. Recently, L. chinensis has been characterized by an improved random amplified polymorphic DNA (RAPD) and inter-simple sequence repeat (ISSR) analysis. The goal of this study was to develop sequence-characterized amplified region (SCAR) markers from the improved RAPD fragments for the genetic analysis of L. chinensis. Results The improved RAPD fragments from L. chinensis were cloned, sequenced and converted into stable SCAR markers. Sequencing of three cloned RAPD fragments revealed that the clone L7-16 consisted of 222 nucleotides (GenBank accession number KM235222), clone L9-6 consisted of 648 nucleotides (GenBank accession number KM235223), and clone L11-26 consisted of 369 nucleotides (GenBank accession number KM235224). Then, specific primers for SCAR markers L7-16, L9-6, and L11-26 were designed and synthesized. PCR amplification was performed using DNA templates from 24 different samples, including 6 samples of L. chinensis and other plants. The SCAR marker L9-6 was specific for all of the L. chinensis samples, the SCAR marker L11-26 specific for five L. chinensis samples, and the SCAR marker L7-16 only specific for the samples from Luzhou. Conclusions This study developed stable SCAR markers for the identification of L. chinensis by the cloning of the improved RAPD fragments. Combining RAPD and SCAR markers provides a simple and reliable tool for the genetic characterization of plant species. <![CDATA[<strong>Genetic diversity in two Italian almond collections</strong>]]> Background Sweet-seeded domesticated almonds were brought to the Mediterranean Basin from central Asia about 4000 years ago. In Italy, most of the almonds produced are cultivated in the southern part of the country. Local populations of the tree in Sardinia are largely seed-derived and mostly self-incompatible, so have developed extensive genetic diversity. The need to protect biodiversity has prompted a revived interest in local genetic materials in almond. Two Italian collections have been established, one in Sardinia and the other in Apulia. These collections were the focus of the present evaluation of genetic diversity. Results Eleven SSRs (microsatellites) were used for fingerprinting. The Sardinian germplasm was highly polymorphic, revealing a mean of 14.5 alleles per locus and a mean heterozygosity of 0.71. Using a model-based clustering approach, two genetic clusters were distinguished: one included all the commercial varieties and most of the Sardinian accessions, and the other most of the Apulian accessions. A similar structure was produced using a distance-based cluster analysis. The Sardinian accessions could still be distinguished from the commercial germplasm with few exceptions. Conclusion The extensive genetic variability present in the Sardinian and Apulian almond germplasm indicates that these materials represent an important source of genes for the improvement of the crop. <![CDATA[<strong>Cultivation of </strong><em><b>Scenedesmus dimorphus</b></em><strong> for C/N/P removal and lipid production</strong>]]> Background CO2 emission, water pollution and petroleum shortage are the issues coming with the development of industry. A cost effective system was constructed to fix the CO2 in flue gas (15% CO2), remove nitrogen and phosphorus from manure wastewater and produce biofuels at the same time. The significant cultivation conditions were selected by Plackett-Burman design, and then optimized with central composite design. Results Optimum culture condition was predicted at light intensity of 238 µmol·m- 2·s- 1, TN of 152 mg·L- 1, inoculum density of 0.3 g·L- 1, under which the measured CO2 fixation rate, total nitrogen and phosphorus removing rate, and lipid content were 638.13 mg·L- 1·d- 1, 88.16%, 73.98% and 11.9%, respectively. The lipid content was then enhanced to 24.2% by a nitrogen starvation strategy. Conclusion A cultivation strategy was suggested to achieve effective C/N/P removal from flue gas and manure wastewater, and meanwhile obtained high lipid content from microalgal biomass. <![CDATA[<strong>Effect of nickel chloride on </strong><em><b>Arabidopsis</b></em><strong> genomic DNA and methylation of 18S rDNA</strong>]]> Background In recent years, nickel (Ni) has been widely applied in industrial and agricultural production and has become a kind of environmental pollution. In this study, the effect of nickel chloride (NiCl2) with different concentrations on Arabidopsis genomic stability and DNA methylation has been demonstrated. The nucleolus variation and 18S rDNA methylation after NiCl2 treatment have been analyzed. Results The results are as follows: (1) The NiCl2 could result in heritable genomic methylation variations. The genomic DNA methylation variations have been detected by methylation-sensitive amplified polymorphism (MSAP) molecular markers, and the result showed that after NiCl2 treatment, there was methylation variation in T0 generation seedlings, and partial site changes maintained in T1 generation, which suggested that the effects of NiCl2 on DNA methylation could be heritable in offspring. (2) NiCl2 brought deformity and damage to nucleolar structure in Arabidopsis root tip cells, and the damage was positively correlated with the NiCl2 concentration. 3. In the nucleolus, there was an increased cytosine methylation in 18S rDNA. The plant nucleolus variation and 18S rDNA methylation may be used as an examination indicator for Ni pollution in soil or plant. Conclusions NiCl2 application caused variation of DNA methylation of the Arabidopsis genomic and offspring's. NiCl2 also resulted in nucleolar injury and deformity of root tip cells. The methylation rate of 18S rDNA also changed by adding NiCl2. <![CDATA[<strong>Non-destructive </strong><em><b>in vitro</b></em><strong> selection of microspore-derived embryos with the fertility restorer gene for CMS </strong><em><b>Ogu</b></em><strong>-INRA in winter oilseed rape (</strong><em><b>Brassica napus</b></em><strong> L.)</strong>]]> Background Microspore embryogenesis and cytoplasmic male sterility system (CMS) are two approaches widely exploited in Brassica napus breeding for production of homozygous doubled haploid (DH) lines and F1 hybrids respectively. Cytoplasmic male sterility system (CMS) is one of the most important pollination systems for hybrid seed production and utilisation of doubled haploid system to quickly prepare fully homozygous fertility restorer lines for CMS Ogu-INRA is very beneficial. Generally, only a small part of microspore-derived embryos is used for plant regeneration, without any knowledge about their properties. Therefore, the possibility of early detection of desirable genotypes bearing a single dominant nuclear fertility restorer (Rfo) gene, can double the success of selection and reduce the production costs. Results To maximize the efficiency and yield of regenerated microspore-derived embryos (MDEs) with the Rfo gene, a protocol for reliable and early, non-destructive selection of desired MDE genotypes was developed. The total amount of 636 cotyledonary embryos was tested by PCR, out of which 37% (237/636) were shown to bear the Rfo gene (instead of 50% according to the expected 1:1 segregation ratio for a single copy gene) and 218 of these fertility restorer plants were fully grown to flowering stage. New molecular marker has been demonstrated to have 100% of co-segregation with the phenotypic evaluation. Conclusion Technique developed in this study provides early and non-destructive sampling of embryonic tissue and the use of new markers for simple and efficient control of the presence of Rfo gene in all accessions.