Surface sterilization for isolation of endophytes: Ensuring what (not) to grow

Author(s):  
Pramod K. Sahu ◽  
Jyotsana Tilgam ◽  
Sushma Mishra ◽  
Saima Hamid ◽  
Amrita Gupta ◽  
...  
2011 ◽  
Vol 236-238 ◽  
pp. 2939-2944 ◽  
Author(s):  
Ri Ya Jin ◽  
Shuang Qi Hu ◽  
Zhi Chao Chi

Experiments were conducted to investigate the effect of concentration and duration of chlorine dioxide gas treatment on Surface sterilization of grape at 25°C. The results showed that the values of inactivate bacterial log reduction ofBotrytis cinerea,Penicilliumandalternariaincreased with the increasing of ClO2gas concentrations and treatment time. When the concentrations and treatment time was about 10 mg/m3and 30 minutes, respectively, more than 4 log reduction was obtained for the three spoilage bacteria on grape surface. Furthermore, the effect of chlorine dioxide gas treatment on quality of grape was investigated. It was found that the contents of vitamin C (Vc) and reducing sugar (RS) in grape also increased compared with grape without ClO2gas treatment.


2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Maria João Pereira ◽  
Helena Fagundo ◽  
Tiago Menezes ◽  
João Couto

This work investigates the potential propagation by seed and cuttings of the Azorean nativeCalluna vulgaris(L.) Hull. for landscape conservation. With that purpose we have performed several germination and cuttings trials, using plant material from wild populations of this species. In the germination trials, we tested the effects of photoperiod length (8 and 16 h), temperature (10, 15, 20, and 20–10°C), seed age (6, 108, and 270 days), temperature of seed storage (4°C and room temperature), and seed surface sterilization on the germination characteristics. In the cuttings trials, we tested the effects of stem cutting type, cultural conditions, cuttings’ harvest month, and rooting substrates on the rooting percentages. The best percentages of germination, 93 and 90%, were obtained with fresh seeds and surface sterilized and sown under an 8 h photoperiod and with temperatures of 10°C or 15°C, respectively; germination after seed storage during 270 days is significantly superior (71%) when seeds are stored at 4°C. The best percentages of rooting were achieved for straight (96%) or heel cuttings (90%) harvested in March, planted on soil from natural stands ofC. vulgarisandErica azoricaHochst., outdoors in half shade, and partially covered with transparent polyethylene film.


Mycorrhiza ◽  
1999 ◽  
Vol 9 (2) ◽  
pp. 65-68 ◽  
Author(s):  
S. W. Budi ◽  
S. Gianinazzi ◽  
B. Blal

Bionatura ◽  
2021 ◽  
Vol 6 (4) ◽  
pp. 2187-2192
Author(s):  
Rashid Rahim Hateet ◽  
Zainab Alag Hassan ◽  
Abdulameer Abdullah Al-Mussawi ◽  
Shaima Rabeea Banoon

The present study aimed to optimize cultural conditions for optimum bioactive metabolite production by endophytic fungus Trichoderma harzianum, isolated by surface sterilization method from the leaf of the eucalyptus plant. The fungus was identified based on morphological characterization. Fungal metabolites were carried out by ethyl acetate solvent. The antibacterial activity was tested against Escherichia coli (ATCC 25922) and Staphylococcus aureus (NCTC 6571). Various carbon, nitrogen sources, pH, temperature, incubation period, and NaCl on the antibacterial metabolite production were studied. Bioactive metabolite production of T. harzianum exhibits a broad spectrum of in vitro antibacterial activity against two strains of bacteria. For the optimum production of bioactive metabolites, Dextrose and Glucose were found to be the best sources of carbon and the best sources of Nitrogen Yeast extract (YE) and (NH4)2SO. The maximum production of bioactive metabolites occurs at pH 7 and 25°C.; the NaCl showed a positive influence on bioactive metabolites.


2008 ◽  
Vol 74 (10) ◽  
pp. 3138-3142 ◽  
Author(s):  
Haiping Li ◽  
Mehrdad Tajkarimi ◽  
Bennie I. Osburn

ABSTRACT Vacuum cooling is a common practice in the California leafy green industry. This study addressed the impact of vacuum cooling on the infiltration of Escherichia coli O157:H7 into lettuce as part of the risk assessment responding to the E. coli O157:H7 outbreaks associated with leafy green produce from California. Vacuum cooling significantly increased the infiltration of E. coli O157:H7 into the lettuce tissue (2.65E+06 CFU/g) compared to the nonvacuumed condition (1.98E+05 CFU/g). A stringent surface sterilization and quadruple washing could not eliminate the internalized bacteria from lettuce. It appeared that vacuuming forcibly changed the structure of lettuce tissue such as the stomata, suggesting a possible mechanism of E. coli O157:H7 internalization. Vacuuming also caused a lower reduction rate of E. coli O157:H7 in stored lettuce leaves than that for the nonvacuumed condition.


1981 ◽  
Vol 27 (1) ◽  
pp. 52-56 ◽  
Author(s):  
L. V. Wood ◽  
R. V. Klucas ◽  
R. C. Shearman

Turfs of 'Park' Kentucky bluegrass reestablished in the greenhouse and inoculated with Klebsiella pneumoniae (W6) showed significantly increased nitrogen fixation (acetylene reduction) compared with control turfs. Mean ethylene production rates per pot were 368 nmol h−1 for K. pneumoniae treated turfs, 55 nmol h−1 for heat-killed K. pneumoniae treated turfs, and 44 nmol h−1 for untreated turfs. Calculated lag periods before activity was observed were generally very short (less than 1 h).When 'Park' Kentucky bluegrass was grown from seed on soil-less medium of Turface, a fired aggregate clay, inoculation with K. pneumoniae (W6) resulted in 9 of 11 turfs showing nitrogenase activity (mean ethylene producion rate per pot was 195 nmol h−1). Only 3 of 11 turfs treated with heat-killed K. pneumoniae showed any activity and their mean rate of ethylene production (40 nmol h−1 per pot) was significantly lower than that for turfs treated with K. pneumoniae.Using the 'Park'–Turface soil-less model system it was shown that acetylene reducing activity was (i) root associated, (ii) generally highest at a depth of 1–4 cm below the surface, (iii) enhanced by washing excised roots, and (iv) inhibited by surface sterilization of excised roots. Klebsiella pneumoniae was recovered from Turface and roots showing acetylene reducing activity.


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