Hoạt tính kháng nấm của tinh dầu Citrus trên vi nấm Achlya sp. gây bệnh trên cá lóc

2021 ◽  
Vol 57 (CĐ Thủy Sản) ◽  
pp. 153-159
Author(s):  
Đặng Thụy Mai Thy ◽  
Trần Thị Tuyết Hoa ◽  
Nguyễn Trọng Tuân

Nghiên cứu nhằm khảo sát hoạt tính kháng nấm của tinh dầu Citrus trên vi nấm Achlya sp. Tinh dầu từ vỏ của chanh giấy (Citrus aurantifolia), chanh núm (Citrus limon (L.) Burn.f.1768), bưởi da xanh (Citrus grandis var. Da xanh), bưởi năm roi (Citrus grandis var. Nam roi), cam sành (Citrus nonbillis) và cam mật (Citrus sinensis) được trích ly bằng phương pháp chưng cất lôi cuốn hơi nước. Hoạt tính kháng nấm, nồng độ ức chế tối thiểu (MIC), nồng độ kháng nấm tối thiểu (MFC) của tinh dầu được thực hiện với vi nấm Achlya sp. A.1910 và Achlya sp. A1924 gây bệnh trên cá lóc. Tinh dầu vỏ chanh giấy và vỏ cam mật có hiệu quả kháng nấm Achlya sp. tốt nhất ở nồng độ 0,78 mg/mL sau 24 giờ. Nồng độ MIC của tinh dầu vỏ bưởi năm roi và vỏ chanh núm từ 1,56 – 6,3 mg/mL. Khả năng kháng nấm của các chiết xuất tinh dầu lần lượt là vỏ chanh giấy, vỏ cam mật, vỏ bưởi năm roi và vỏ chanh núm. Sợi nấm Achlya sp. không phát triển khi ngâm trong tinh dầu Citrus ở các nồng độ 100, 50, 25 và 12,5 mg/mL.

2021 ◽  
Vol 58 (04) ◽  
pp. 1373-1377
Author(s):  
Muhammad Shah Nawaz ul Rehman

Citrus fruit production is largely affected by different bacterial and fungal pathogens. In Pakistan bacterial diseases like citrus bacterial canker (CBC) pose severe risk to citrus economy. Diagnoses of such diseases could be helpful to avoid the epidemics in nurseries or orchids. In 2011-12, citrus canker symptoms i.e., callus-like outgrowths on leaves and fruits of grape fruit (Citrus paradisi), Washington naval (Citrus sinensis), Kaghzi Limon (Citrus aurantifolia swingle), lemon (Citrus Limon) and pomelo (Citrus maxima) were noticed in Sargodha district of Punjab, Pakistan. Bacteria i.e., yellow mucoid, Xanthomonas- like isolates, were isolated from these lesions. Bacteria isolated from these lesions were cultured and total DNA was isolated. A diagnostic fragment of 581 bp based on rpf genes of Xanthomonas citri pv. citri was amplified, cloned and completely sequenced. BLAST and evolutionary analysis revealed that these isolates show 100% sequence similarity and group with Xanthomonas citri subsp. citri from Argentina (CP023285) and Reunion (CP018858), (CP018854). To our knowledge, this is the first formal report of X. campestris pv. citri pathotypes A on Citrus paradise, Citrus sinensis, Citrus maxima, Citrus Limon and Citrus aurantifolia swingle in Pakistan


2021 ◽  
Vol 21 (105) ◽  
pp. 18950-18964
Author(s):  
EO Irokanulo ◽  
◽  
BW Oluyomi ◽  
CO Nwonuma

Essential oils (EOs) obtained from a wide variety of plants have become popular with increased scientific interest as potential natural agents for food preservation. Two concentrations of rind EOs (400 mg/ml and 200 mg/ml) from three species of citrus fruit; Citrus sinensis (Sweet orange), Citrus limon (Lemon), and Citrus aurantifolia (Lime) were used to treat fresh chicken meat inoculated with Escherichia coli ATCC 25922, Salmonella typhi ATCC 20971 and Salmonella enterica ATCC 14028 to evaluate their protective abilities on bacteria-contaminated meat The EOs were extracted from the ground rinds by hydro-distillation. Alongside the EOs, sodium nitrate (NaNO3) was used as a positive control preservative. A viable count was carried out to determine the bacteria load reduction on the inoculated fresh chicken meat. After 24 hours of treatment, the results showed that the EOs had no adverse effect on the physical attributes of the meat: the color and smell of the chicken meat were unaltered compared with the negative control (None EO and NaNO3 treated meat) that showed evidence of putrefaction through color change and foul smell. The two- lime rind EOs concentrations used to treat the Escherichia coli ATCC 25922 inoculated meat reduced the viable count of the organism by 7.9 log compared to the Escherichia coli ATCC 25922-inoculated meat which received no rind EOs or NaNO3 treatment. Other results showed that sweet orange (SO) rind EOs (400 mg/ml and 200 mg/ml) treatment of meat inoculated with Salmonella enterica ATCC 14028 had similar but mild preservative effects as both treatments reduced the log of the bacteria by 1.1 and 0.8, respectively. In comparison with NaNO3, the EOs treatment had a significant (p<0.05) preservative effect on the bacteria-inoculated meats. Findings from this study, therefore, suggest that Citrus spp. rind EOs have good potential as natural preservative for chicken meat. However, notwithstanding the relative positive organoleptic results observed in this study, further investigations on the prolonged preservation effect of the EOs on the physical attributes of fresh chicken meat need to be undertaken.


2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Moira Carmalita Dharsika Niluxsshun ◽  
Koneswaran Masilamani ◽  
Umaramani Mathiventhan

Wide application of nanoparticles motivates the need for synthesising them. Here, a nontoxic, eco-friendly, and cost-effective method has been established for the synthesis of silver nanoparticles using extracts of lemon peel (Citrus limon), green orange peel (Citrus sinensis), and orange peel (Citrus tangerina). The synthesised nanoparticles have been characterised using UV-visible absorptionspectroscopy, Fourier transform infrared spectroscopy, and transmission electron microscopy (TEM). The UV-visible absorption spectrum of these synthesised silver nanoparticles shows an absorption peak at around 440 nm. TEM images show different shaped particles with various sizes. Furthermore, the antibacterial activity of silver nanoparticles was appraised by a well-diffusion method and it was observed that the green synthesised silver nanoparticles have an effective antibacterial activity against Escherichia coli and Staphylococcus aureus. The outcome of this study could be beneficial for nanotechnology-based biomedical applications.


Agriculture ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 33 ◽  
Author(s):  
Beatrice Falcinelli ◽  
Franco Famiani ◽  
Andrea Paoletti ◽  
Sara D’Egidio ◽  
Fabio Stagnari ◽  
...  

Seeds from Citrus species represent a relevant by-product of the juice industry and a potential source of bioactive compounds such as phenols and other antioxidants. Sprouting could be an intriguing idea to enhance the content of these compounds, as explored for other fruittree species. In this experiment, the sprouting performance, the concentration of total phenols and phenolic acids, and the antioxidant activity of seeds and sprouts were evaluated for bitter orange (Citrus aurantium L. seedlings), blonde orange (Citrus sinensis (L.) Osbeck cv.Biondocomune), sweet orange (Citrus sinensis (L.) Osbeck seedlings), lemon (Citrus limon (L.) Osbeck cv.Femminello), and mandarin (Citrus reticulata Blanco cv.Tardivo di Ciaculli). The germination was high for all genotypes except for mandarin, but it took 4–8 weeks. Sprouts did not differ among genotypes for size and generally had hard consistency of cotyledons and a bitter taste. The concentrations of total phenols and phenolic acids of seeds and sprouts varied with the genotype, while the antioxidant activity was not statistically different among treatments. Sprouting increased both the concentration of phenolic compounds and antioxidant activity but no correlation was found between them, suggesting that other antioxidants, besides phenols, are present. Given the slow germination and the bitter taste, Citrus sprouts appear unsuitable for homemade production aimed at direct consumption, while they may have perspectives for extraction of food additives, cosmetics, and pharmaceutics.


2012 ◽  
Vol 48 (1) ◽  
pp. 284-290 ◽  
Author(s):  
Loredana Abbate ◽  
Nicasio Tusa ◽  
Sergio Fatta Del Bosco ◽  
Tonia Strano ◽  
Agatino Renda ◽  
...  

1985 ◽  
Vol 25 (3) ◽  
pp. 718 ◽  
Author(s):  
PJ Sharkey ◽  
CR Little ◽  
IR Thornton

Winter-maturing Lisbon lemons (Citrus limon (L.) Burm.f.) and Ellendale tangors (Citrus reticulata x Citrus sinensis (L.) Osbeck) which had been dipped in fungicides and waxed, developed less than 10% rot but remained fresh for only 2-3 months in cool-storage at 10�C and 80-90% RH. High-density polyethylene (HDPE) wraps delayed loss of firmness and peel coloration of tangors and lemons for 5 and 8 months respectively, in cool-storage, but both citrus developed unacceptable levels of rotting within 4 months of harvest. Perforated low-density polyethylene liners were less effective than HDPE wraps for preserving fruit condition but they extended the storage life of lemons until early January (6 months) without incurring levels of decay greater than 10%. However, tangors cool-stored in liners became unsaleable after only 3-4 months owing to loss of acidity and flavour.


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