Production and characterization of Pectic enzymes from three fungi

Pectins are compounds  that  are resistant   to  enzymatic  cleavage  in most  organisms  and  plants, Studies  were  therefore  made towards finding methods for hydrolyzing these compounds. One such approach  is enzymatic hydrolysis.  Three fungi   (Trichoderma   viride,    Asperigillus     niger   and penicillum   digitatum)  are   used   for  production   of   pectinase  enzymes, Two  methods (reducing  sugar and viscometary)  were  used  for  measuring enzymes activities. Pectin and sodium polypectate compounds were used  as substrates. The  production of  pectinases by the three fungi was investigated in culture media. T. viride and P. digitatum  gave  maximum   production  of pectinase  enzymes  after  two  week  and  A. niger  gave  it  after  one week. Purification   by   ammonium    sulphate   precipitation,     showed   that   the maximum  pectinase  activity  was  at   80%   concentration for both fungi A niger and P. digitatum. By using  gel  electrophoresis, five bands were found to   give   pectinase  enzymes   activities. The   present   study   showed    the importance   of   fungi   as   sources  of  enzymes and recommends that more studies  must   be   done   in   the  field of  biotechnology to produce glucose  from natural products by  using fungi. &nbsp

Factors Affecting Activity of Cellulose Enzymes Produced By Three Fungi

Three fungi (Trichoderma viride, Asperigillus niger and Penicillium digitatum) were used in the present study for the production of the cellulase enzymes (carboxymethylcellulase and cellobiase). The effects of different metal ions on the activities of these enzymes were , caused a ++and Mn+ , K++, Ba++using the reducing group method. The addition of Ca investigatedsignificantly higher increase in the activity of the carboxymethylcellulase enzyme of the three . However, the addition ++and Zn++ e a less increase was found by the addition of Mgfungi, whilactivity. The activity of the is enzyme caused a decrease in th ++, and Fe++, Cu++, Cd+, Ag+of Naand +ence of Hg, but it was decreased in the pres+and K ++cellobiase was increased with Caat the was occurred A. nigerenzyme produced by cellobiasehe higher activity of the T.++Cd, however, ++Ca and ++900 ppm for Mn –500 , while it occurred at+900 ppm of K –200 of range P. and T. viride ase of bothobiFor the cell 900 ppm. –800 of at the range it occurred ,++Ba for . ++, no significant different was noticed with different concentrations of Cadigitatumfungi at all th ase enzyme of boobigave a lower activity for the cell ++On the other hand, Ba concentrations. The optimum temperature for the carboxymethylcellulase enzyme activity was at . P. digitatum and T. viride bothfor C 050 –C 0it was between 40 , whileA. niger50°C for C.0However, the optimum temperature for the cellobiase activity of the three fungi was at 40 The optimum activity of the carboxymethylcellulase enzyme produced by A. niger was at pH 4, and for that of T. viride was at pH 6. Two peaks were detected for the same enzyme produced by P. digitatum, at pH 6 and pH 7. However, the optimum pH value for the cellobiase enzymes produced by the three fungi was at pH 4.0only

Growth and Survival of Some Microorganisms on Cotton Fabrics Treated with Extracts of Mesquite (Prospuis juliflora

 The present study investigated the effects of the aqueous extracts of mesquite on growth and survival of two bacteria. The results of the study showed that the aqueous extracts of the different plant parts of mesquite were highly effective in suppressing bacterial growth. However, the aqueous extracts were more effective against the gram-positive bacterium (Staphylococcus  aureus) compared to the Gram-negative bacterium ( E. coli). Extracts of mesquite plant were also effective in decreasing the survival ability of the two tested bacteria on cotton fabrics, although the effects were more pronounced against the Gram-positive bacterium (Staphylococcus  aureus)

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

Physiochemical Characteristic and Biological Activity of the Clove (Syzygium aromaticum) Bud Oil

  The present study was investigating the physiochemical and the biological activity of the Clove bud oil against the fungus (A. niger) and two bacteria (E. coli and Staph. aurues). The inhibition zone plate method was used for bacterial test, while the mycelia weights and radial growth methods were used for the fungal study. The A.O.S. official methods were used to determine the physiochemical properties. The studies on the physiochemical characteristics of the Clove bud oil proved that the acid value was (3.86), the saponification value was (38.27),the peroxide value was (3.83), the specific gravity was (1.043), the  reflective index was (1.525), the iodine value was (182.43), and the free fatty acid was (1.94). The results of the antimicrobial tests showed that  the  Clove bud oil gave a complete inhibition of the radial growth of the fungus (A. niger) at its higher concentration and a high reduction percent at its lower concentrations. However, the mycelial fresh and dry weights of the fungus A. niger were completely inhibited by the Clove bud oil at its higher concentration, and clearly reduced at its lower concentrations. The inhibition zone of growth of both bacteria was larger than that of the control treatment. Clove bud oil showed clear inhibition zone when used against Staph. aurues compared to its use against E. coli. Many studies have reported that oils of different herbs and spices can yield medicinal compounds. Spices and herbs have been used for thousand of years by man in traditional medicine. However, more physiochemical characterizations need to be done and the antifungal and the antibacterial properties should be verified in any further studies on the Clove bud oil.   &nbsp

Effect of Groundnut Pod Condition on the Microbial Content and Aflatoxin Contamination in the Groundnut Seeds

The present study was investigated the effect of groundnut pod condition on the microbial content and aflatoxin contamination in the groundnut seeds in Sudan, which collected from irrigated area (Gezira) and rain-fed area (Al-fao and Kordofan). The samples were investigated for their fungal growth using potato dextrose agar (PDA) media and for their aflatoxin contamination using thin layer chromatography (TLC) technique. High percentage of the groundnut seeds were found unshelled sound intact (53.33-63.00%), while the low percentage was unshelled shrink/damaged (10.33-19.34%). The infection by A. flavus and aflatoxins contamination were found to be high in the split samples either shelled or unshelled which collected from Gezira area (56.67%), whereas, the low percentage was (10.00%) in the unshelled shrink/damaged samples which collected from Kordofan area. Microbial content showed that the sound intact seeds either shelled or unshelled were free from A. flavus and aflatoxins, while the split and shrink/damaged samples either shelled or unshelled were infected by A. flavus and contaminated by aflatoxins. Moreover, High percentage of fungs infection other than A. flavus were obtained (40.00-43.33%) in split and shrink/damaged shelled samples, however, low percentage were obtained (10.00%) in intact samples either shelled or unshelled which collected from Gezira are

Production and Characterization of Pectic Enzymes of Xanthomonas campestris pv. sesami

إنتاج ودراسة خصائص الإنزيمات البكتينية للبكتيريا Xanthomonas campestris pv. sesami   ملخص الدراسة            البكتيريا  Xanthomonas campestris pv. sesami ، هي المسبب لمرض تبقع أوراق نبات السمسم. الأنزيمات البكتينية التي تنتج بواسطة العديد من البكتيريا الممــرضة للنبات اتضـح أنها تلعب دوراً هاماً في عمــلية الأمراض. هنالك ثلاث أنواع رئيـسـية من الإنزيمات البكــتينية (بوليجلاكتيورونيز، PG وبوليجلاكتيورونيت ترانس - امنيز، PTE و بكتين ميثايل - اٍستريز، PME). هـدف هذا البحث على دراسة قدرة البكتيريا، X.  campestris pv. sesami  على إنتاج الإنزيمات البكتينية المختلفة. استخدم في هذه الدراسة وسط غذائي من الأملاح مضافاً إليه مواد بكتينية مختلفة كمصدر للكربون. الإنزيمات المنتجة تمت دراسة خصائصها باستخدام اختبارات محددة. أوضحت النتائج أن البكتيريا كانت قادرة إنتاج الإنزيم بوليجلاكتيورونيت ترانس - اٍمنيز ((PTE فقط ولم تنتج الانزيم بكتين ميثايل - اٍستريز، PME)). أشارت النتائج الى أن ملح بولي بكتات الصوديوم وحمض البولي جلاكتيورونيك  هي الأفضل لإنتاج هذا الإنزيم حيث أعطت  9 .26 و 19.8 وحدات لزوجة إنزيمية، على التوالي. . كان أعلى إنتاج للإنزيم في اليوم السادس (9.3 وحدات لزوجة)  ثم انخفض الإنتاج مع زيادة فترة التحضين. اختبار تأثير درجة الأس الهيدروجيني أوضح أن الدرجة المثلى لنشاط  الإنزيم كانت 9.0. أظهرت دراسة اختبار تاثيز ايونات لمعادن مختلفة على نشاط الانزيم أن أيونات الكالسيوم هي التي أعطت اكبر نشاط 12.2  وحدة لزوجة. وعند اختبار تراكيز مختلفة من  ايونات الكالسيوم ووجد ان اعلى نشاط كان على التركيز  50 ملج / مل حيث أعطى 18.0 وحدة لزوجة. توصي الدراسة على اختبار قدرة البكتيريا على انتاج إنزيمات السليولوز وشبه السليولوز والتي لها دور ايضاً في عملية الاٍمراض.       The bacterium Xanthomonas campestris pv. sesami, is the causal organism of the leaf spot disease (Marad eldum) in sesame plants. Pectic enzymes which were reported to be produced by many plant pathogenic bacteria,  were found to play an important role in pathogenesis. There are three main types of pectic enzymes (Polygalacturonase, PG, Polygalacturonate trans-eliminase PTE and Pectin methylesterase PME). The present study was conducted to investigate the capacity of the bacterium X. campestris pv. sesami,  to produce the different types of pectic enzymes. A salt medium supplemented with different pectic materials as carbon sources were tested for the production of the enzymes. The produced enzymes were characterized using different selective tests, both the viscosity and reducing group methods were used to measure the enzyme activity. The results showed that no pectin methylestrease (PME) was produced and only the Polygalacturonase trans-eliminase (PTE) was produced by the bacterium. Sodium polypectate and polygalacturonic acid were found as the best substrates giving 26.9 and 19.8 viscosity enzyme units, respectively. The enzyme activity was maximum at the 6th day (9.3 viscosity units), then the activity was decreasing with further incubation time. The test of the effect of the pH indicated that the  pH optimum of the enzyme activity was at pH 9.0. The effects of different metallic ions to the enzyme activity showed that,= a higher activity was found with Ca++ which gave 12.2 viscosity    units. When different concentrations of Ca++ were tested, the maximum activity of the enzyme was found at 50 mg/ ml concentration, which gave 18.0 viscosity units. It could be recommended that the tested bacterium should be investigated for the production of the cellulases and hemi-cellulases which also have a role in the pathogenesis process

Survival of Staphylococcus aureus and Escherichia coli on Cotton Fabrics Treated with Extracts of Garad (Acacia nilotica

The transfer of pathogenic bacteria and other microorganisms among patients in hospitals is a growing concern. One of the critical aspects of bacterial transmission from a person (patient or a health care worker) to the environment and then to another person is the ability of the microorganism to survive on various common hospital materials, such as fabrics (Neely and Maley, 2000). Lee et al. (1969) found that Salmonella typhimurium, can remain viable and infectious on different fabrics, for relatively long periods of time. However, garments of health care workers are considered an important aspect of the environment that can easily become contaminated (Johnson, 1977). Fabrics treated with antimicrobial agents (antibiotics), are therefore, gaining popularity as a new promising area of research (Lee et al, 1969). However, antibiotic resistant strains of some bacteria such as the multi-resistant Staphylococcus aureus and vancomycin-resistant enterococci, have already been reported (Kim et al., 1998; Neely and Maley, 2000). Plant extracts were suggested by many authors as an alternative to antibiotics. However, plant extracts were found effective against microorganisms since the beginning of the human civilization (Gilliver, 1947; Dix, 1974 and Zainal et al., 1988). For inoculation, bacterial isolates of Escherichia coli and Staphylococcus aureus, which were obtained from the Food Microbiology Lab, University of Gezira, were grown in a nutrient agar medium (NA)

Antimicrobial Activity and Some Physiochemical Properties of Pumpkin (Cucurbita pepo L.) Seed oil

Pumpkin and squash plants grow in warm, humid regions,  cannot withstand frost. Most of the pumpkin consumed in Sudan was grown in Kordufan (western sudan).The use of plants and their extracts as remedies for curing many diseases have stimulate studies for investigating the presence of effective antimicrobial substances in them The present study was investigating the physiochemical and the biological activity of the different solvent extracts of pumpkin (Cucurbita pepo) seed oil (hexane, ethanol, methanol, and water) against two fungi  (A. niger and P. italicum) and two bacteria (E.coli and Staph. aureus).The inhibition zone method  was used for bacterial tests and the mycelia weight method was used for the fungal study. The results of the physiochemical showed that the specific gravity of the oil was between 0.997–0.908. The Refractive index was between 1.46–1.470. The average iodine value was 117.97,  the free fatty acids was between 0.2 and 0.55. The peroxide value was in the normal range (5.92–9 and the average saponification value was about 188. The biological study showed that the fresh and the dry weights of mycelia were highly reduced, although the reduction was only statistically different at the higher concentrations (75-100%).The fresh weights for the higher concentrations were 1.65 and 1.0 and for the lower concentrations were 3.1 and 3.7 for both A. niger and P. italicum, respectively. The inhibition zone of growth of both bacteria was far greater than that of the control treatment. The results indicated that the pumpkin oil extracts are more effective against bacteria compared to fungi. The hexane extract  was giving a large  inhibition zone (about 26.5 mm diameter) while, the ethanol extract was giving a less inhibition zone (about 14.2.mm diameter). On the other hand both methanol and the aqueous extracts were giving very low inhibition zones (13.5 and 13.6 mm diameter, respectively). However, more physiochemical characterizations need to be done  and the antifungal and the antibacterial properties  should verified in any further  studies on the pumpkin seed oil