Antagonistic, biofilm-forming rhizospheric Pseudomonas spp. isolated from Hail province

Background: The objectives of this study were to characterize Pseudomonas rhizospheric strains, that have a biocontrol activity, in rhizosphere soil in Hail province and study their ability to form biofilm.Methods: Rhizosphere soil samples were collected from rhizosphere of soil plantation areas, to be used for bacteria isolation. The identified bacteria were qualitatively tested for their ability to produce slime and subsequently develop biofilm.Results: The cultural and biochemical identification techniques, including morphological, biochemical and molecular methods revealed that the antagonistic bacteria- from the distinctive rhizosphere soil samples belong to Pseudomonas genus in particular, P. aeruginosa (PF1a, pf2a, PF-8) and P. putida (PF-7). These identified isolates inhibited Aspergillus niger development with percentage of parasitic growth inhibition greater than (48.095 ± 2.182)% for P. aeruginosa (pf-8). In addition, these identified isolates were significantly shown to be able to produce exopolysaccharide and subsequently develop biofilm on polystyrene and glass surfaces.Conclusion: Superior strains of these bio-control and plant growth promoting rhizobacteria will enable for better biological control of fungal and bacterial plant diseases and may reduce chemical pesticide usage. The indigenous strains isolated could potentially have a great impact on controlling plant diseases, in particular, those caused by microorganisms, and could be used as an alternative bio control agents instead of harmful chemical pesticides. Most of the tried microbes produced exopolysaccharides as well as formed biofilm on polystyrene and glass surfaces.Keywords: Biological control, Rhizosphere; Biofilm; Pseudomonas; Antimicrobial

Effects of Some Essential Oils on Aspergillus flavus Growth and Aflatoxin Production

The present study aimed at investigating the effects of some essential oils on inhibiting fungal growth of A. flavus and aflatoxin production. Clove oil was found as the best among the six different oils tested against the radial growth at the concentration of 0.05. mL/100ml. However the other oils were also significantly better than the control except the Pumpkin oil. Different concentrations (0.00, 0.01, 0.03 and 0.05 ml/100ml) of only three of the oils were tested against the radial growth of A. flavus. Clove and Cumin oils were significantly effective than the control at all these concentrations. Although Pumpkin oil was slightly more effective than the control at its higher concentration (0.05) ml/100ml), it was not effective at its lower concentrations (0.01 and 0.03 ml/100ml). Clove oil was also the best in suppressing mycelial growth at the concentration of 0.05 ml/100ml. However, the other oils were also significantly better than the control, while, Pumpkin oil was non-effective. Spore germination was also affected by the oils tested. Clove oil gave complete inhibition at its higher concentration followed by Cumin, Rehan, Garlic and Desert date, while Pumpkin oil was the least one. Aflatoxin production was highly affected by the essential oils tested. Clove and Cumin exhibited a complete inhibition, followed by Rehan; Garlic and Desert date while Pumpkin oil was non-effective

The Free Amino Acid Composition of The Sudanese Fermented Camel's Milk (Garris)

      Many  workers   have   investigated  the  composition  of  milk and milk   proteins   of   various   species  of   domestic   animals   but   the information regarding  the composition of  fermented  camel 's   milk is  still  limited. The  fresh  camel  milk  contains 3.3-4.7% protein, 2.8 - 3.6%  fat, 4.0 - 5.2%  lactose,  0.7%  ash, 9.2 - 15.4% total solids,  and  to has  a  pH of  6.0-6.5  (Abdel  Rahim, 1987). The casein of camel  milk  is  richer  in  proline  and   threonine than cow's  milk, but poorer in alanine, arginine, glycine and serine (Hoeller and Hassan, 1965)

Extraction of Pectin from Tamarind Fruits (Tamarindus indica L.) and its Utilization in Jam Production

     In the present work, pectin was extracted from tamarind fruit pulp and used for jam production. The pectin yield in one kg tamarind pulp was 3.7 grams. The average chemical composition of tamarind pulp was: 5.44 % protein, 2.44 % ash, 18.21 % moisture, 1.99 ± 0.8% fat, 13.05 ± 0.7% fiber and 55% available carbohydrates. The tamarind fruit pulp also contained appreciable amounts of minerals as follows: 134 (mg/100g) sodium, 74 (mg/100g) potassium and 88 (mg/100g) calcium. The chemical, microbiological and sensory quality characteristics of the extracted pectin jam (A) as well as commercial pectin jam (B) were also determined. (A) contained: 8.5 % total sugar, 5 % reducing sugar, 67 % total soluble solid, 36 mg/100g sodium, (60 mg/100g potassium, 80 mg/100g calcium and had a pH value of 3.3. On the other hand, (B) contained:    12 % total sugar, 1.3 % reducing sugar, 68 % total soluble solid, 44 (mg/100g) sodium, 43 (mg/100g) potassium, 64 (mg/100g) calcium and had a pH value of 3.5±0.1. Microbiological analysis of (B) had shown high levels of yeast and mould, however, the counts of yeast and mould was highly reduced in (A). The sensory analysis indicated that all types of jams were accepted by panelists who generally preferred (B) than (A) due to its appealing colour and flavour

Utilization of Some Local Date Palm Cultivars in Production of Jam and Assessment of its Quality

The objective of the present work was to study the possibility of the production of jamfrom three local cultivars of dates, namely; Jawa, Gondaila and Kulma. The chemical,microbiological and sensory characteristics of date jams were determined. The analysisrevealed relative increase of moisture content in Kulma date jam (KDJ) (54.62%) ascompared with those of Jawa date jam (JDJ) and Gondaila date jam (GDJ) which were51.09% and 47.94%, respectively. The ash content was 1.7%, 0.4%, and 0.5% in (JDJ),(GDJ) and (KDJ); respectively. The total soluble solids was 80.5%, 80.8% and 78% in(JDJ), (GDJ) and (KDJ); respectively. Reducing sugars were higher in (JDJ) (34.0%)when compared with those of (KDJ) and (GDJ) which were 31% and 24%; respectively.Titrable acidity was 0.4%, 0.32% and 0.37% in (JDJ), (GDJ) and (KDJ); respectively.The highest pH value was found in (GDJ) (4.7) as compared with (JDJ) and (KDJ) whichwere 4.39 and 4.22, respectively. The highest value of ascorbic acid was found in (KDJ)(220 mg/100g) as compared with (JDJ) and (GDJ) which were 150 and 176 mg/100g;respectively. On the other hand, the microbiological analysis of date jam samplesrevealed low levels of total microbial load. The sensory evaluation indicated highacceptability for all samples of date jam

The effect of wildfires on wood-decay fungi in the Great Smoky Mountains National Park

Background: In late November and early December of 2019, wildfires occurred over portions of the Great Smoky Mountains National Park. More than 4,000 ha were affected by the wildfires. The objective of the research reported herein was to access the impact of these wildfires on the assemblages of wood-decay fungi associated with the study areas in the park.Methods: The investigated fungi were confined to two study areas; the first subjected to a relatively high intensity burn and the second subjected to a relatively low intensity burn. In addition to specimens of fungi obtained in the field, small pieces of coarse woody debris were assembled, brought back to the laboratory and placed in plastic chambers for incubation and kept moist. Over the course of two months, fruiting bodies appearing in these incubation chambers were observed and collected. All specimens from both the field and incubation chambers were identified from sequences of the internal transcribed spacer (ITS) region of the ribosomal DNA.Results: A total of 31 different taxa were identified along with nine taxa reported previously as unknown and uncultured. However, almost all of these records were from the study area subjected to the relatively low intensity burn.Conclusion: The relatively high intensity burn site was almost completely devoid of wood-decay fungi.Keywords: Great Smoky Mountains National Park; ITS ribosomal DNA region; Wood-decay fung

Production and Quality Evaluation of Vinegar from Tamarind (Tamarindus indica L.) Fruit Pulp

ABSTRACT       Vinegar is a liquid consisting mainly of acetic acid (CH3COOH) and water. The acetic acid is produced by the fermentation of ethanol by acetic acid bacteria. This study aimed to produce vinegar from tamarind fruit pulp and evaluation of its quality. Samples of tamarind fruit were collected from different sites in Sudan: Gedaref (GT), Damazin (DT) and Obeid (OT). The vinegar yields from 1 kg tamarind pulp from (GT), (DT) and (KT) were 300, 200, 260 ml, respectively. The physical characteristics of tamarind fruit pulp and its seeds were determined. The average fruit length, width and weight were 14.28± 0.31mm, 11.06± 1.1mm and 12.33± 0.7g, respectively The production of vinegar was carried out at three stages. The concentration of acetic acid of the produced vinegar from (GT), (DT) and (OT) were equivalent to (16.2%), (19%) and (17.7%), and pH values of these samples were found to be (2.2), (1.9) and (2.0), respectively. The study recommends the efficient industrial use of tamarind fruit in many products such as vinegar.&nbsp

Isolation, Identification and Characterization of Candida utilis from Some of the Sudanese traditionally Fermented Food Products

The aims of this study were to isolate, identify and characterize the yeast Candida utilis (as a source of single cell protein SCP) from various local Sudanese fermented foods (Kissra, Hulu Mur and Marisa). Hulu Mur samples were found to contain the highest counts of yeast (6.89 cfu/g 6.78 cfu/g) while the low counts were found in Kissra samples (5.95 cfu/g - 5.84 cfu/g). Most of the C. utilis isolates had the same biochemical profiles with some slight variations. The study showed that C. utilis can utilize aerobically and anaerobically dextrose, sucrose, and raffinose and could assimilate maltose under aerobic conditions only. The isolates could not utilize lactose, glactose. cellubiose and arabinose under both aerobic and anaerobic conditions. It had an ability to assimilate nitrate and grew at high concentration of ethanol. The study showed that the biomass yield of C utilis was 2.5 g\l using batch fermentation. On the other hand the protein and moisture content of the product were 42% and 61%, therefore. It can be used in the production of single cell protein (SCP)

Design of a small-scale solar Dryer to Improve Natural Drying of Vegetables and Fish

This study aimed at improvement of a solar dryer based on the principle of natural–convection used for drying vegetables and fish. The constructed dryer, comprises of three main models, solar collector (tent of polythene sheet collector), drying chamber and solar chimney. Design has been made to eliminate the problem of quality loss and over drying. Okra, Tomato, onion, fish were subjected to solar drying and open – air drying processes. The chemical, microbiological analyses and sensory evaluation were carried out for the dried products. The results gives indication of improved quality for solar dryer compared to products dried in open – air systems which indicates its efficiency in drying. &nbsp