Bacterial Profiles and Physico-chemical Parameters of Water Samples from Different Sites of the New Calabar River, Nigeria

Abstract Water samples were collected from three sites (Ogbakiri, Choba and Iwofe) of the New Calabar River and were evaluated for microbiological and physico-chemical characteristics. Bacterial isolates consisting mainly of gram-negative bacteria (Escherichia coli, Proteus vulgaris, Acinetobacter spp, Pseudomonas aeruginosa, Enterobacter aerogenes, Klebsiella spp., Vibrio sp. and Nocardia asteroides) were isolated from the samples. The highest total coliform counts log 10 2.9 were encountered in water samples from Iwofe but the lowest counts log 10 1.9 occurred in the water samples from Ogbakiri. Ecological parameters varied among the sites with the highest pH value of 7.87 occurring at Iwofe and lowest of 6.12 at Choba. Maximum salinity level of 15 0 / 00 was observed at Iwofe and lowest at Choba. In contrast, maximum dissolved oxygen of 10.1ppm was observed at Choba and the minimum at Iwofe. The different bacterial profiles are probably attributable to the anthropogenic and industrial activities of the sites

Evaluation of Biochemical and Quality Attributes to Monitor the Application of Heat and Cold Treatments in Tomato Fruit (Lycopersicon Esculentum Mill.)

The study was accomplished to optimize the application of stress treatment to prevent chilling injury (CI) in tomatoes. Four treatments were evaluated: control, heat shock applied for 24 (HS24) and 48 h (HS48), and cold shock applied for 24 h (CS24). The fruits were stored at 2 and 14C, and evaluated immediately after treatment and after 21 and 28 days of storage. An additional evaluation after 7 days of exposure at 20C following storage withdrawal was included to induce ripening and exteriorize the development of CI symptoms. Different biochemical and quality attributes were evaluated (color, titratable acidity, firmness, ethylene, CI index and heat shock protein [HSP] accumulation). Heat treatments were successful in preventing the decay of fruits under CI‐inducing conditions. The significantly better performance of HS48 in comparison to the other treatments gives evidence that the effectiveness relies on the adequate intensity of application; therefore, this intensity should be strictly controlled by a proper monitoring method. In this regard, small HSP accumulation was found suitable to reflect properly the physiological condition of fruits and therefore to potentially optimize and determine the adequate intensity of treatment application.Instituto de Tecnología de AlimentosFil: Polenta, Gustavo Alberto. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto Tecnología de Alimentos; ArgentinaFil: Budde, Claudio Olaf. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria San Pedro; ArgentinaFil: Sivakumar, Dharini. Tshwane University of Technology. Department of Crop Science. Postharvest Technology Group; SudáfricaFil: Nanni, Mariana. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto Tecnología de Alimentos; ArgentinaFil: Guidi, Silvina Mabel. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto Tecnología de Alimentos; Argentin

Bacterial Profiles and Physico-chemical Parameters of Water Samples from Different Sites of the New Calabar River, Nigeria

Water samples were collected from three sites (Ogbakiri, Choba and Iwofe) of the New Calabar River and were evaluated for microbiological and physico-chemical characteristics. Bacterial isolates consisting mainly of gram-negative bacteria (Escherichia coli, Proteus vulgaris, Acinetobacter spp, Pseudomonas aeruginosa, Enterobacter aerogenes, Klebsiella spp., Vibrio sp. and Nocardia asteroides) were isolated from the samples. The highest total coliform counts log10 2.9 were encountered in water samples from Iwofe but the lowest counts log101.9 occurred in the water samples from Ogbakiri. Ecological parameters varied among the sites with the highest pH value of 7.87 occurring at Iwofe and lowest of 6.12 at Choba. Maximum salinity level of 150/00 was observed at Iwofe and lowest at Choba. In contrast, maximum dissolved oxygen of 10.1ppm was observed at Choba and the minimum at Iwofe. The different bacterial profiles are probably attributable to the anthropogenic and industrial activities of the sites

Mannitol-enhanced survival of Lactococcus lactis subjected to drying

Survival of Lactococcus lactis subjected to different drying conditions was investigated. Mannitol most remarkably enhanced the survival of dried cells to a level almost equalling that of viable cells [log10 (cfu ml-1) = 9.42] as was found prior to the drying process (log10 = 9.6). In the absence of mannitol, a survival was reduced by a factor of 104. Drying of cells at 20 °C led to higher survival rates than drying at 30 °C. Mannitol enhanced the survival rate at both temperatures, and at both 20 °C and 30 °C the highest reduction in survival occurred when cells were dried at a water activity of 0.76. In the presence of mannitol, differences in survival after drying at different water activities were less pronounced. Rehydration of cells dried in the presence of mannitol resulted in an extended lag phase of 4 h compared to fresh cells. No growth or acidification of the culture medium was observed for 12 h in the case of rehydrated cells dried in the absence of mannitol. It was hypothesized that a radical scavenging activity of mannitol could partly explain these observations

Modified Atmosphere Packaging and Biodeterioration of Plantain

Fruits of two local plantain cultivars and a disease-resistant tetraploid hybrid were subjected to modified atmosphere packaging. The same organisms namely Colletotricum musae, Botryodiplodia theobromae, Fusarium monilifomae, Aspergillus niger and Aspergillus flavus, were isolated from the local cultivars and the hybrid fruits. Pathogenicity tests showed that local cultivars were more susceptible to Botryodiplodia theobromae and Fusarium monilifomae, while the hybrid fruits were more susceptible to Colletotricum musae. It was observed that Aspergillus niger and Aspergillus flavus isolated did not show any pathogenicity indicating that colonization of plantain fruits and its hybrids is metabiotic. At ambient temperature, there was delay in biodeterioration, ripening, and weight loss. This resulted into increased shelf life. The responses of the hybrid fruits to fungal attack and the physicochemical changes that took place had the same trend, with the fruits of the local cultivars showing that the hybrid will be a good substitute when it is eventually introduced as a cultivar. The most obvious advantage of modified atmosphere packaging is the extension of shelf life of plantain and plantain hybrid fruits without the use of chemical preservatives. Int. J. Agric. Rural Dev., 2003, 4: 53-5

Staphylococcus aureus Profile of Some Selected Processed Foods

Processed foods are supposed to be free of pathogenic and spoilage microorganisms but this is not always true. This study is, therefore, designed to determine the presence of Staphylococcus aureus in some locally processed foods. One hundred and sixty samples of sixteen different types of processed foods and beverages were purchased from different locations in Calabar, Cross River State and microbiologically analyzed for possible contamination with Staphylococcus aureus using Compact Dry X-SA plate. The presence of S. aureus was in 38 (23.8%) of the samples and the total Staphylococcal counts ranged between 1.2 x 102 cfu/g(ml) and 4.8 x 104  cfu/g(ml), with the highest count recorded in burger and the least load in Rosenberg. The food samples with the positive S. aureus were Rosenberg with 30% incidence rate, meat pie with 90%, burger 100%, donut 100% and moi moi 60% incidence rates.  The presence of Staphylococcus aureus in some of these foods analyzed is an indication of poor hygienic practices and important health threat to consumers. A total of 45 distinct colonies were isolated and screened for coagulase positive characteristics. Out of the 45 isolates, 15(33%) were coagulase positive.  The implication of this is that the consumption of these food products can lead to staphylococcal food borne disease. It is, therefore, very important for proper hygienic processing and handling practices to be employed for these foods and similar ones