Genomics assisted functional characterization of Paenibacillus polymyxa HK4 as a biocontrol and plant growth promoting bacterium.

The diseases caused by phytopathogens account for huge economic losses in the agricultural sector. Paenibacillus polymyxa is one of the agriculturally important biocontrol agents and plant growth promoting bacterium. This study describes the antifungal potential of P. polymyxa HK4 against an array of fungal phytopathogens and its ability to stimulate seed germination of cumin and groundnut under in vitro conditions. The cumin and groundnut seeds bacterized with HK4 exhibited enhanced germination efficiency in comparison to controls. The use of HK4 as a soil inoculant significantly promoted the shoot length and fresh weight of groundnut plants in pot studies. The draft genome analysis of HK4 revealed the genetic attributes for motility, root colonization, antagonism, phosphate solubilization, siderophore production and production of volatile organic compounds. The bacterium HK4 harnessed several hydrolytic enzymes that may assist its competence in the rhizosphere. The PCR amplification and sequence analysis of the conserved region of the fusA gene amplicon revealed the ability of HK4 to produce fusaricidin. Furthermore, the LC-ESI-MS/MS of crude cell pellet extract of HK4 confirmed the presence of fusaricidin as a major antifungal metabolite. This study demonstrated the potential of HK4 as a biocontrol agent and a plant growth promoter.

Inactivation of Salmonella enterica and Enterococcus faecium NRRL B2354 on cumin seeds using gaseous ethylene oxide.

The objectives of this study were to investigate the effects of processing parameters (relative humidity (RH), temperature, and exposure time) on the ethylene oxide (EtO) microbial inactivation of Salmonella spp. and to evaluate Enterococcus faecium NRRL B2354 as a suitable surrogate for Salmonella inactivation on cumin seeds. Five grams of cumin seeds inoculated with either Salmonella or E. faecium were treated with EtO at different temperatures (46, 53, and 60 °C) and RH (30, 40, and 50%) levels for different exposure time to investigate the effects of process parameters on the microbial inactivation. The Weibull model fit the survival data of both bacteria with a shape parameter p < 1, which showed a tailing effect with concave shape indicating that the sensitive cells were inactivated first, and the sturdy ones survived at low RH treatment conditions. In general, the log reductions of both bacteria on cumin seeds increased with the increasing RH and temperature for EtO treatment. RH is a critical factor for successful EtO inactivation treatment. RH must be higher than 40% to implement a successful and efficient EtO decontamination of cumin seeds. E. faecium consistently showed lower log reductions than those of Salmonella under all EtO treatment conditions investigated in this study, demonstrating that E. faecium is a suitable surrogate for Salmonella. Twenty minutes of EtO treatment at 50% RH achieved ~5 log reductions of both bacteria at all three temperatures. A response surface model was developed to predict the log reductions of both bacteria under different treatment conditions and the contour plots representing log reductions were created. Inactivation is positively correlated to temperature and RH. Therefore, a higher temperature is required to achieve the desired log reduction at lower RH and vice versa. The developed response surface model is a valuable tool for the spice industry in identifying the possible combinations of EtO process parameters (temperature, RH, and exposure time) required to achieve a desired microbial reduction of Salmonella for ensuring microbial food safety of spices.

Efecto in vitro antimicrobiano de comino (cuminum cyminum) sobre porphyromonas gingivalis / Antimicrobial in vitro effect of cumin (cuminum cyminum) on porphyromonas gingivalis

El uso de las plantas como métodos alternativos de medicina viene incrementándose con el paso del tiempo, es así que la Organización Mundial de Salud mediante políticas sanitarias, ayuda a las autoridades y promueve el desarrollo de fitofármacos, con la utilización segura y eficaz de la medicina tradicional y complementaria, con la reglamentación de productos, prácticas y profesionales. La investigación tiene tres etapas; la primera consta de un estudio etnofarmacológico, realizado en la Provincia de Manabí, donde se estableció que el comino presenta un nivel de uso significativo (UST) de 20% e índice de valor de uso (IVU) de 1,4.La segunda, marcha fitoquímica, estableció la presencia de metabolitos secundarios como terpineol y acido cumínico relacionados con la acción antimicrobiana. La tercera evaluó el efecto in vitro antimicrobiano del aceite esencial y extracto etanólico de Comino sobre Porphyromonas gingivalis, mediante técnica de difusión de disco en agar Mueller Hinton-Sangre; se midieron concentraciones al 25%, 50%, 75% y 100% de aceite esencial y extracto etanólico de comino; se usó amoxicilina como control positivo y agua destilada como control negativo. Los efectos inhibitorios del extracto etanólico y aceite esencial fueron de 84,08% y 89,76% respectivamente, presentando una sensibilidad media según la escala de Duraffour. En cuanto a la estadística se utilizó ANOVA, determinándose los valores para aceite esencial p=0.008; y el extracto etanólico p=0.001, lo que concluye que las hipótesis nulas son rechazadas. (AU)

Inoculation Preparation Affects Survival of Salmonella enterica on Whole Black Peppercorns and Cumin Seeds Stored at Low Water Activity.

Salmonellosis has been increasingly associated with contaminated spices. Identifying inoculation and stabilization methods for Salmonella on whole spices is important for development of validated inactivation processes. The objective of this study was to examine the effects of inoculation preparation on the recoverability of Salmonella enterica from dried whole peppercorns and cumin seeds. Whole black peppercorns and cumin seeds were inoculated with S. enterica using one dry transfer method and various wet inoculation methods: immersion of spice seeds in tryptic soy broth (TSB) plus Salmonella for 24 h (likely leading to inclusion of Salmonella in native microbiota biofilms formed around the seeds), application of cells grown in TSB, and/or application of cells scraped from tryptic soy agar (TSA). Postinoculation seeds were dried to a water activity of 0.3 within 24 h and held for 28 days. Seeds were sampled after drying (time 0) and periodically during the 28 days of storage. Salmonella cells were enumerated by serial dilution and plated onto xylose lysine Tergitol (XLT4) agar and TSA. Recovery of Salmonella was high after 28 days of storage but was dependent on inoculation method, with 4.05 to 6.22 and 3.75 to 8.38 log CFU/g recovered from peppercorns and cumin seeds, respectively, on XLT4 agar. The changes in surviving Salmonella (log CFU per gram) from initial inoculation levels after 28 days were significantly smaller for the biofilm inclusion method (+0.142pepper, +0.186cumin) than for the other inoculation methods (-0.425pepper, -2.029cumin for cells grown on TSA; -0.641pepper, -0.718cumin for dry transfer; -1.998pepper for cells grown in TSB). In most cases, trends for reductions of total aerobic bacteria were similar to those of Salmonella. The inoculation method influenced the recoverability of Salmonella from whole peppercorns and cumin seeds after drying. The most stable inoculum strategies were dry transfer, 24-h incubation of Salmonella and spices in TSB (i.e., potential inclusion of Salmonella within native microbiota biofilms), and inoculation of Salmonella cells grown on TSA subsequent to drying. However, with the dry transfer method it was difficult to obtain the large amount of inoculum needed for inactivation studies.

Combined effects of gamma-irradiation and modified atmosphere packaging on quality of some spices.

Thyme (Thymus vidgaris L.), rosemary (Rosmarinus officinalis L.), black pepper (Piper nigrum L.) and cumin (Cuminum cyminum L.) in ground form were packaged in either air or 100% N2 and γ-irradiated at 3 different irradiation levels (7kGy, 12kGy, 17kGy). Total viable bacterial count, yeast and mould count, colour, essential oil yield and essential oil composition were determined. Microbial load was not detectable after 12kGy irradiation of all samples. Irradiation resulted in significant changes in colour values of rosemary and black pepper. The discolouration of the irradiated black pepper was lower in modified atmosphere packaging (MAP) compared to air packaging. Essential oil yield of irradiated black pepper and cumin was lower in air packaging compared to MAP. Gamma-irradiation generally decreased monoterpenes and increased oxygenated compounds, but the effect was lower in MAP. Overall, spices should be irradiated under an O2-free atmosphere to minimise quality deterioration.

Effect of ultraviolet and far infrared radiation on microbial decontamination and quality of cumin seeds.

UNLABELLED: Cumin seeds might be exposed to a high level of natural bacterial contamination, and this could potentially create a public health risk besides leading to problems in exportation. Ultraviolet (UVC) and far infrared (FIR) radiation has low penetration power, and due to that, there might be no detrimental defects to the products during a possible decontamination process. Therefore, the objective of this study was to determine the effect of UVC and FIR treatment on microbial decontamination and quality of cumin seeds. For this purpose, FIR treatment at different exposure times and temperatures were applied followed by constant UVC treatment with an intensity of 10.5 mW/cm² for 2 h. Total mesophilic aerobic bacteria of the cumin seeds were decreased to the target level of 104 CFU/g after 1.57, 2.8, and 4.8 min FIR treatment at 300, 250, and 200 °C, respectively, following a 2 h UVC treatment. Under the given conditions, a complete elimination for total yeast and molds were obtained while there were no significant changes in volatile oil content and color of the cumin seeds. Consequently, combined UVC and FIR treatment was determined to be a promising method for decontamination of the cumin seeds. PRACTICAL APPLICATION: This research attempts to apply UVC and far infrared (FIR) radiation for pasteurization of cumin seeds. The data suggested that combined UVC and FIR radiation treatments can become a promising new method for pasteurization of cumin seeds without causing any detrimental defect to the quality parameters. The results of this industry partnered (Kadioglu Baharat, Mersin, Turkey--http://www.kadioglubaharat.com) study were already applied in industrial scale production lines.

Cometabolic degradation of trichloroethene by Rhodococcus sp. strain L4 immobilized on plant materials rich in essential oils.

The cometabolic degradation of trichloroethene (TCE) by Rhodococcus sp. L4 was limited by the loss of enzyme activity during TCE transformation. This problem was overcome by repeated addition of inducing substrates, such as cumene, limonene, or cumin aldehyde, to the cells. Alternatively, Rhodococcus sp. L4 was immobilized on plant materials which contain those inducers in their essential oils. Cumin seeds were the most suitable immobilizing material, and the immobilized cells tolerated up to 68 muM TCE and degraded TCE continuously. The activity of immobilized cells, which had been inactivated partially during TCE degradation, could be reactivated by incubation in mineral salts medium without TCE. These findings demonstrate that immobilization of Rhodococcus sp. L4 on plant materials rich in essential oils is a promising method for efficient cometabolic degradation of TCE.

Avaliação microbiológica de condimentos artesanais e industrializados da grande Recife, PE / Microbiological evaluation condiment artisan industrialized in Recife, PE

Os condimentos são importantes do ponto de vista microbiológico, já que quando produzidos e/ou comercializados em condições higiênicas precárias, favorecem o crescimento de microrganismos. Considerando tal fato, foram realizads análises microbiológicas em canela, colorífico, cominho e pimenta do reino artesanais e obtidos industrialmente , quanto ao Número Mais Provável (NMP) de coliformes; contagem de Staphylococcus aureus, Bacillus cereus, fungos e leveduras e pesquisa de Escherichia coli e Salmonella spp. Os resultados foram analisados através de Modelos Lineares Generalizados (GLM), com processo de Stepwise, ao nível de 5,0 por cento de probabilidade. Resultados negativos foram obtidos em todas as amostras para Staphylococcus aureus; a presença de Salmonella spp só foi confirmada em duas (2,08 por cento) amostras de condimentos industrializados (ComC e PrD), estando estes condimentos em condições sanitárias insatisfatórias e impróprios para o consumo humano; todas as amostras estavam em condições sanitárias satisfatórias de acordo com a legislação vigente para coliformes fecais; a presença de Escherichia coli foi confirmada em dez (10,42 por cento) das 96 amostras analisadas; 16 (16,67 por cento) amostras apresentavam-se contaminadas por B. cereus, estando três (3,13 por cento) dentro do padrão microbiológico e 13 (13,5 por cento) fora dos padrões aceitáveis; 40 (41,67 por cento) amostras estavam dentro dos padrões microbiológicos para fungos e leveduras, enquanto que 46 (47,92 por cento) estavam acima do limite estabelecido. Os resultados demonstraram que os condimentos, quando produzidos e/ou comercializados em condições higiênico-sanitárias insatisfatórias, podem veicular microrganismos potencialmente patogênicos.