STUDY OF THE ANTIBACTERIAL ACTIVITY OF PLANT-DERIVED MEATABOLITES AGAINST PHYTOBACTERIA IN RICE CULTURE

Bacterial blast of the rice panicle, caused by the Gram-negative bacterium Burkholderia glumae, causes grain rot, generating losses of 15 to 80% of production. Although integrated management methodologies and the use of agrochemicals have been implemented to mitigate this situation, satisfactory results have not been achieved, and the excessive use of oxolinic acid has generated resistance on the part of the bacterial strains and, on the other hand, the safety of the final product for food safety worldwide. The present study aimed to implement new environmentally friendly biocontrol strategies such as the use of essential oils of Lippia alba and Lippia origanoides to reduce losses in rice crops caused by B. glumae, finding significant results of the essential oils, observing antibacterial activity of 100%, Lippia origanoides at a concentration of 90 ppm.   Lippia alba had inhibitory activity at 1550 ppm with 80% effectiveness. The chemical profiles of the essential oils showed thymol as the major secondary metabolite with an area percentage of 68% for the essential oil of L. origanoides, while L. alba contains geranial and neral in 35% and 29% respectively and are possibly associated with antibacterial activity against B. glumae and its future use for the biological management of bacterial blast in rice plants

Diferencia esperada de progenie como herramienta de selección para peso al destete en ganado Brahman

Objetivo. Determinar la diferencia esperada de progenie (DEP’s) para el peso al destete (PD) en ganado Brahman como criterio de selección de futuros reproductores. Materiales y métodos. Se utilizaron 552 registros (PD) recolectados entre 1997 y 2007 de la hacienda Mundo Nuevo (San Onofre, Sucre, Colombia), provenientes de 33 padres. El modelo estadístico utilizado incluyó los efectos fijos de año y época de nacimiento, sexo del ternero, número de partos de la vaca y el efecto aleatorio del padre. Para el análisis, se utilizó el método de los cuadrados mínimos mediante el procedimiento PROC GLM, contenido en el statistical analysis system (SAS). La heredabilidad fue estimada con los componentes de varianza entre y dentro de toro, obtenidos por el procedimiento PROC VARCOMP. Las diferencias esperadas de progenies (DEP’s), fueron calculadas a través del método de mejor predictor lineal insesgado (BLUP). Resultados. La media del PD fue 238.5 ± 31.6 kg. Los efectos de padre, sexo, número de partos y año de nacimiento fueron significativos (p≤0.05). La heredabilidad para PD fue 0.43 ± 0.15. Las DEP’s variaron entre -16.9 y + 17 kg, con una exactitud (EXA) que osciló entre 0.71 y 0.78. Conclusiones. La significancia de las diferentes fuentes de variación de PD coincide con la mayoría de los reportes referenciados en la literatura. El valor estimado de la heredabilidad para PD, indica que se puede lograr progreso genético para PD. Los resultados de las (DEP’s) evidenciaron que el 52% de los toros aportan variaciones negativas para PD

Genetska raznolikost kolumbijskog kreolskog magaraca u odjelu Sucre

The objective of this study was to evaluate the genetic diversity of the Colombian Creole donkey in the Department of Sucre using Random Amplified Microsatellites (RAM) molecular markers. In 100 individuals from the five subregions of the department, DNA was extracted and five RAM primers were amplified by PCR. In all, 291 bands were found, on average 11.96±1.45 per primer, the highest value in CCA (18±2.23) and the lowest in TG and GT (8.8±0.44). CA was the most polymorphic primer (88.09±10.91%) with the highest heterozygosity value (He) (0.376±0.021), while the lowest was GT (0.341±0.076 and 0.101±0.040, respectively). Intrapopulation analysis showed an average of 66.50±1.72 bands, of which 89.86±24.04% were polymorphic. The highest number of bands (63±3.84) was found in the Gulf of Morrosquillo (GO) subpopulation, and the lowest in Mojana (MO) (48±2.88); however, the highest value of polymorphic loci (81.16%) and He (0.335±0.022) were found in the Montes de María (MM) subpopulation, making it the most diverse. The average genetic diversity for the entire population was 0.351±0.021 bands. The population structure analysis showed a 10% variation between subpopulations, with an FST value of 0.17±0.01 (P<0.05). Genetic distances between subpopulations showed that MO and GO were the most distant. The RAM markers are effective in assessing the genetic diversity of the Creole donkey, which has high values of genetic diversity, particularly the MM subpopulation. The genetic revealed structure could be the result of natural geographical barriers between the subregions.Cilj ove studije bio je procijeniti genetsku raznolikost kolumbijskog kreolskog magaraca iz odjela Sucre koristeći molekularne markere tipa RAM-a (engl. Random Amplified Microsatellites). U 100 jedinki iz pet podregija odjela izlučeno je DNK, a pomoću PCR-a amplificirano je pet primera RAM-a. Pronađene su 291 trake, prosječno 11,96±1,45 po primeru, najveća vrijednost u CCA (18±2,23), a najniža u TG i GT (8,8±0,44). Najviši polimorfni primer (88,09±10,91 %) i s najvišim He (engl. heterozygosity value (0,376±0,021) bio je CA, dok je najniži bio GT (0,341±0,076 i 0,101±0,040). Intrapopulacijska analiza pokazala je prosječno 66,50±1,72 pojasa, od kojih je 89,86±24,04 % bilo polimorfno. Subpopulacija Gulf of Morrosquillo (GO) imala je najveći broj opsega (63±3,84), a najmanju je pronašla u Mojana (MO) (48±2,88), međutim, najveću vrijednost polimorfnih lokusa (81,16 %) i He (0,335±0,022) pronašli su u subpopulaciji Montes de María (MM), koja je najraznolikija. Ustvrđena prosječna genetska raznolikost iznosila je 0,351±0,021 za cijelu populaciju. Analiza populacijske strukture pokazala je 10 % odstupanja između subpopulacija, s vrijednosti FST-a od 0,17±0,01 (P<0,05). Genetske udaljenosti između subpopulacija pokazale su da su MO i GO najdalje. RAM markeri učinkoviti su za procjenu genetske raznolikosti kreolskog magaraca, ova kreolska pasmina ima visoke vrijednosti genetske raznolikosti, MM subpopulacija je najraznolikija, pronađena genetska struktura može biti rezultat prirodnih geografskih barijera između podregija

Use Of Cymbopogon Citratus Leaf Essential Oil For Management Of Anthracnosis In Yam-Grops

The essential oil of Cymbopogon citratus (DC.) Stapf. (Lemongrass) has been positioned as a phytosanitary alternative to counteract the effects caused by phytopathogenic fungi. The aim of the present study was to evaluate in vitro the inhibitory activity of essential oils from Cymbopogon citratus (lemongrass) leaves against Colletotrichum gloeosporioides. Leaves of the silver species Cymbopogon citratus were collected in the sub-region of the savannahs of the department of Sucre; for the extraction of essential oils (EO), fresh leaves were weighed and EO was obtained using the microwave-assisted hydrodistillation method. The antifungal activity of the EOs was evaluated using the surface seeding technique on solid medium, the activity was expressed as percentage inhibition index. Chemical characterisation of the essential oils was performed by gas chromatography coupled to mass spectrometry. The highest antifungal index efficiency of lemongrass was observed at concentrations of 5,000, 8,000 and 10,000 ppm. The main constituent identified in lemongrass EOs was citral, which is possibly related to the inhibitory activity of the fungus causing anthracnose disease in yam crop

Evaluation of the potential of Chlorella vulgaris for the removal of pollutants from standing water

In this study we evaluated the microalga Chlorella vulgaris in order to determine the ability of the microalga to remove the highest concentration of contaminants present in stagnant water. A mixing design of the microalgae with the wastewater was carried out for 20 days, with a 12:12 h photoperiod, in a greenhouse. The highest removal efficiencies for heavy metals were ≥ 98% (mainly Cd, Hg, As and Pb) and ≥ 90% for BOD5, COD, nitrates, phosphates, total phosphorus, faecal and total coliforms. Finally, according to the design analysis, it was determined that the optimal microalgae mixture 1:10 achieves the highest DO production and the highest removal, in a cultivation time of 15 days. In conclusion, microalgae demonstrate their capacity for bioremediation of rural domestic wastewater jagüeyes

Remediation of wastewater from the semi-artisanal tanning process using microalgal consortium

Human, commercial and industrial activities are polluting the waters that are normally used for agricultural productivity. The Ministry of the Environment (MAE) regulates these activities by demanding, according to environmental legislation, that the water collected be returned upstream in equal or better conditions than the initial ones, and within the parameters of the unified text of environmental legislation when it is discharged into the sewage system. The poor disposal of liquid effluents with the presence of chromium by various industries, especially tanneries, is causing pollution of water bodies. The percentage removal efficiency was presented 10 days after the start of the experiment, showing the highest removal for the heavy metals cadmium, arsenic and lead at 100%, followed by a reduction in the amount of total coliforms (98), faecal coliforms (100), total solids (78) and nitrates (97%). The removal of total phosphorus corresponded to 72%, while for total phosphorus it was 72%.&nbsp; It is also observed that the biological oxygen demand (BOD5) was reduced by 82% and the biochemical oxygen demand (COD) by 89% with respect to the initial values found reported in tannery wastewater before the experiment. Alternately these effluents could be used as alternative substrates for the growth of microalgae, which would generate a positive impact on the total costs of biomass production at large scales

BOD5 AND COD REMOVAL EFFICIENCY BY Chlorella vulgaris IN WASTEWATER FROM TANNING PROCESSES

Microalgae are a very heterogeneous microbial group that provides several applications nowadays, including wastewater treatment. The treatment of wastewater is very important, as it contains pollutants that prevent its reuse. In the present study, the growth potential of the microalga Chlorella vulgaris and its purification capacity in wastewater from tanning processes were evaluated. Ch vulgaris was bioaugmented in a bioreactor, using exponential phase cells of 106 cells/mL. The Ch. vulgaris cells were treated with tanning wastewater for 20 days. BOD5 and COD parameters were measured daily. The results of the organic load degradation tests confirm that Ch. vulgaris reduces BOD5 and COD to values below those permitted by the regulations established for the leather manufacturing, tanning and dressing industry. Ch. vulgaris is able to survive the adverse conditions present in wastewater, efficiently removing pollutants present in wastewater from tanning processes