Antimicrobial effect of a cyclic peptide Nostophycin isolated from wastewater cyanobacteria, Nostoc calcicola

Different types of peptides are produced by cyanobacteria of the genus Nostoc, which are unique in structure and have a wide spectrum of biological activities. The objective of the study to explore different habitats of organism and study antimicrobial activities to improve their pharmaceutical application and drug like properties by structure modification. A cyclic peptide nostophycin was isolated from Nostoc calcicola (MK506349) through freeze dried lyophilization method. Its structure has been elucidated with FT-IR, 1HNMR, 13CNMR and LC-MS. Glycine, d-glutamine, l-phenylamine, d-isoleucine, l-proline and a novel amino acid Ahoa are constituents of nostophycin. 1HNMR, 13CNMR spectroscopy confirmed the number of protons and carbons, and characteristics peak determined the structure and fragmentation pattern through LCMS. Nostophycin possess Ahoa instead of Adha which makes it different from microcystin. Nostophycin exhibits antimicrobial activity against E.coli, S. aureus, C. albicens and A. niger. A good antifungal activity (9-52 μg/mL) and moderate antimicrobial activity (concentration 18-52 μg/mL) were found for nostophycin. In case of already known peptides, these molecules may be further exploited to improve pharmaceutical application and future drug development.

Phân lập Phân lập một số chủng vi khuẩn lam Nostoc từ đất trồng tỉnh Nghệ An và đánh giá sự sinh trưởng, sự cố định nitrogen của chúng

Tóm tắt: Nostoc là một trong những nhóm vi khuẩn lam (Cyanobacteria) có cấu trúc dạng sợi, có tế bào dị hình, quang tự dưỡng, thường phân bố rộng rãi trong đất trồng. Nghiên cứu này trình bày kết quả phân lập một số chủng vi khuẩn lam Nostoc từ đất trồng lúa, cây công nghiệp ở tỉnh Nghệ An và đánh giá sự sinh trưởng, khả năng cố định nitơ phân tử của chúng; hướng đến mục tiêu sản xuất sinh khối vi khuẩn lam Nostoc để làm phân đạm hữu cơ. Kết quả đã phân lập thành công 5 chủng vi khuẩn lam Nostoc, bao gồm 3 chủng biểu hiện màu xanh lam (Nostoc calcicola HN9-1a, Nostoc linckia Cam-C1, Nostoc paludosum ĐT3-02) và 2 chủng biểu hiện màu nâu (Nostoc ellipsosporum NH2X7, Nostoc gelatinosum TT3-05) trong điều kiện ánh sáng trắng. Trong môi trường BG-11 và ánh sáng đèn neon, 3 chủng màu xanh lam sinh trưởng tốt hơn và đạt năng suất sinh khối khô (387 – 431 mg/L sau 21 ngày nuôi) cao hơn so với 2 chủng màu nâu (310 – 370 mg/L sau 21 ngày nuôi). Các chủng vi khuẩn lam Nostoc này đều có khả năng cố định nitrogen; đặc điểm này được nhận biết thông qua sự biểu hiện gen NifD và sự hình thành tế bào dị hình của chúng. Kết quả nghiên cứu cũng cho thấy chủng vi khuẩn lam không có tế bào dị hình Pseudanabaena dictyothalla QV3-11 phân lập từ đất trồng lúa tỉnh Nghệ An không có khả năng cố định nitrogen. Những chủng Nostoc có khả năng cố định nitrogen này có thể làm nguồn nguyên liệu để nghiên cứu theo hướng sản xuất phân bón sinh học.

Occurrence of Nostoc Vaucher ex Bornet And Flahault in Water Bodies of Maldah District, West Bengal

Present investigation deals with systematic enumeration, importance and uses of Genus Nostoc Vaucher ex Bornet and Flahault collected from different water bodies of Maldah District, West Bengal. Six species and one variety of Genus Nostoc Vaucher ex Bornet and Flahault (Nostoc calcicola Bréb. ex Bornet and Flahault, Nostoc carneum C.Agardh ex Bornet and Flahault, Nostoc comminutum Kütz., Nostoc ellipsosporum Rabenh. ex Bornet and Flahault, Nostoc linckia Bornet ex Bornet and Flahault, Nostoc oryzae (F.E.Fritsch) Komárek and Anagn. and Nostoc ellipsosporum var. violaceum C.B.Rao) were recorded from water bodies of out of fifteen, four blocks - Harishchandrapur-I, Harishchandrapur-II, Ratua II and Gazol of Maldah District, West Bengal. Nostoc ellipsosporum var. violaceum C.B.Rao has been reported for the first time from barabilla bil of block Ratua II of Maldah District, West Bengal. Some of the species of Nostoc Vaucher ex Bornet and Flahault are very important and useful in different ways which has been described in this paper.

Cyanobacteria modulated changes and its impact on bioremediation of saline-alkaline soils

Saline-alkaline (Usar) soils have high pH and undesirable salts on their surface. A halotolerant, heterocystous and nitrogen fixing cyanobacterium Nostoc calcicola Breb. BREB grow successfully on salinealkaline soils of Eastern Uttar Pradesh. Soil pot experimentation has been conducted in laboratory condition to study the reclamation of saline-alkaline soils collected from investigated site. Both sterilized and natural soils were taken in earthen pots to observe the changes in soil properties inoculated with cyanobacteria and gypsum. In such treated soils significant decrease in pH, ECe and Na+ have been observed with cyanobacterial application. There also occurs a significant increase in organic carbon. Experimental reclamation of such soils has been found with cyanobacteria with or without gypsum. N. calcicola + gypsum seem to be a suitable combination for reclamation of saline-alkaline soils. This study highlights that a biological amendment with halotolerant cyanobacteria and gypsum in combination shows better option for bioremediation of saline-alkaline (Usar soils).

Antioxidant activity and phycoremediation ability of four cyanobacterial isolates obtained from stressed aquatic system

ABSTRACTCyanobacteria are natural enormous sources of various biologically active compounds with great contributions in different industries. This study aimed to introduce molecular and biochemical characterization for four novel cyanobacterial isolates obtained from Egyptian wastewater canals. Besides, In vitro biological activity of these isolates and their potential ability to take up nutrients and heavy metals from wastewater were examined. The obtained accession numbers were KY250420.1, KY321359.1, KY296359.1 and KU373076.1 for Nostoc calcicola, Leptolyngbya sp, Nostoc sp, and Nostoc sp, respectively. The isolate Leptolyngbya sp (KY321359.1) showed the lowest identity (90%) with other deposited sequences in database. While the isolate Nostoc sp (KU373076.1) showed the highest total phenolic content as well as the highest levels of caffeic, ferulic and gallic acids. Consequently, it appeared the highest antioxidant scavenging activity. All cyanobacterial isolates revealed potent ability to take up nutrients and heavy metals from wastewater. Generally, this study provides a taxonomic and molecular evidence for four novel cyanobacterial isolates with antioxidant activity and potent phycoremediation ability.

ACCUMULATION OF FLAVONOIDS IN SOYBEAN UNDER EFFECTS OF CYANOBACTERIAL CRUDE EXTRACT AND APHID INFESTATION

The differential accumulation of endogenous flavonoids was recorded in soybean (G. max(L.) Merr. cv. “Nam Dan”) under infestation of cowpea aphid (Aphis craccivora Koch) and/ortreatment of the crude extract of cyanobacterium strain Nostoc calcicola HN9-1a. During A.craccivora infestation, flavonoids in the aphid-infested leaves were strongly induced to highcontents, which were 1.84–2.21 - fold higher than that observed in control. Those bioactivesubstances were suppressed by the single treatment of N. calcicola crude extract, however, wereenhanced by the cross-talk interactions of N. calcicola HN9-1a and A. craccivora. Flavonoids inthe double factors-effected soybean leaves were remarkably increased to high level since 24hours after cowpea aphid attack, having by 2.99 - 3.06-fold higher than that in control. It was theimportant evidences to suggest that flavonoids may function in the defense mechanism ofsoybean “Nam Dan” against A. craccivora; and N. cacicola HN9-1a crude extract improved theaccumulation of flavonoids in soybean response to cowpea aphid infestation.

Effect of Cyanobacteria Isolates on Rice Seeds Germination in Saline Soil

Cyanobacteria are prokaryotic photosynthetic communities which are used in biofertilization of many plants especially rice plant. Cyanobacteria play a vital role to increase the plant's ability for salinity tolerance. Salinity is a worldwide problem which affects the growth and productivity of crops. In this work three cyanobacteria strains (Nostoc calcicola, Anabaena variabilis, and Nostoc linkia) were isolated from saline soil at Kafr El-Sheikh Governorate; North Egypt. The propagated cyanobacteria strains were used to withstand salinity of the soil and increase rice plant growth (Giza 178). The length of roots and shoot seedlings was measured for seven and forty days of cultivation, respectively. The results of this investigation showed that the inoculation with Nostoc calcicola, Anabaena variabilis, and Nostoc linkia increased root length by 27.0, 4.0, 3.0 % and 39, 20, 19 % in EC5 and 10 (ds/m), respectively. Similarly, they increased shoot length by 121, 70, 55 %, 116, 88, 82 % in EC5 and 10 (ds/m), respectively. In EC15and more concentrations, control rice plants could not grow while those to which cyanobacteria were inoculated could withstand only EC15 but not other elevated concentrations. These results encourage using Nostoc calcicola,Anabaena variabilis, and Nostoc linkia as biofertilizer for rice plant in the saline soil for increasing growth and decrease soil electrical conductivity.