Azospirillum Actinidiae sp. nov., a Nitrogen-Fixing Bacterium Isolated From The Roots of Kiwifruit Plants

A novel diazotrophic bacterium, designated CCTCC AB 2021101T, was isolated from fresh roots of kiwifruit. Cells of strain CCTCC AB 2021101T were Gram-negative, aerobic and rod-shaped, with motility provided by peritrichous flagella. The 16S rRNA analysis showed that strain CCTCC AB 2021101T belongs to the genus Azospirillum and is closely related to Azospirillum melinis (98.32%), Azospirillum oryzae (97.73%), Azospirillum lipoferum (96.98%), Azospirillum humicireducens (96.49%) and Azospirillum largimobile (96.01%) and lower sequence similarity (<96.0 %) to all other species of the genus Azospirillum. Strain CCTCC AB 2021101T was able to grow well at 35–40℃ and pH 6.0–7.0, and tolerated up to 3.0 % (w/v) NaCl. The major saturated fatty acids are C14:0, C16:0 and C18:0. C18:1 ω7c and C16:0 3-OH were the major unsaturated and hydroxylated fatty acid. The G+C content was 67.8 mol%. Strain CCTCC AB 2021101T gave positive amplification for dinitrogen reductase (nifH gene). Highest nifH gene sequence similarities were obtained with Azospirillum brasilense AWB14T(95.9%), Azospirillum zeae Gr24T(95.56%), Azospirillum picis DSM 19922T(96.79%), Azospirillum lipoferum B22T(94.88%) and Azospirillum oryzae COC8T(94.88%). The activity of the nitrogenase of the strain was further confirmed by acetylene-reduction assay, which was recorded as 81 nmol ethylene h-1. Based on these data, strain CCTCC AB 2021101T is considered to represent a novel endophytic diazotrophs species in the genus Azospirillum, for which the name Azospirillum actinidiae sp. nov. is proposed. The type strain is CCTCC AB 2021101T.

РОСЛИННІ ПРОБІОТИКИ: ВПЛИВ НА РОСЛИНИ В УМОВАХ СТРЕСУ

Світове сільське господарство стоїть на порозі нової революції. Агровиробники прагнуть використовувати менше мінеральних добрив та пестицидів і при цьому отримувати високі врожаї. Одим із інструментів, що можуть сприяти цьому, є рослинні пробіотики. Тому мета цієї статті дослідити вплив корисних мікроорганізмів на сільськогосподарські культури, а саме на те які бактерії чи гриби можуть сприяти в боротьбі рослин проти стресу від посухи, засолених ґрунтів чи патогенів. Важливим аспектом дослідження стала також інформація про те, що міроорганізи позитивно впли-вають на поглинання рослинами поживних речовин. Всі ці фактори негативно впливають на вирощування кукурудзи на силос (Zea mays L.), особливо в умовах швидкої зміни клімату. Для проведення дослідження було проаналізовано літера-турні джерела зарубіжних та вітчизняних авторів. В результаті дослідження було з’ясовано, що на стрес від посухи у посівах кукурудзи впливає Azospirillum lipoferum. На засолених ґрунтах рослини кукурудзи краще переживають стрес за інокуляції рослин Pseudomonas syringae, Enterobacter aerogenes, P. fluorescens, Bacillus aquimaris, Serratia liquefaciens, Gracilibacillus, Staphylococcus, Virgibacillus, Salinicoccus, Bacillus, Zhihengliuella, Brevibacterium, Oceanobacillus, Exiguobacterium, Pseudomonas, Arthrobacter, Halomonas та ін. Дію на патогени в посівах кукурудзи виявляють Pseudomonas fluorescens, Fusarium oxysporum, Fusarium verticillioides, Pseudomonas, Bacillus cereus. На засвоєння рослинами кукурудзи по-живних речовин впливають Pseudomonas alcaligenes, Bacillus polymyxa, Mycobacterium phlei, Burkholderia, Bacillus spp., Herbaspirillum, Enterobacteriales, Streptomyces pseudovenezuelae, Ruminobacter amylophilus, Fibrobacter succinogenes, Enterococcus faecium, Арбускулярні мікоризні гриби, Enterobacter E1S2, Klebsiella MK2R2, Bacillus B2L2, Azospirillum brasilence, Micromonospora, Streptomyces, Bacillus, Hyphomicrobium, Rhizobium, Azohydromonas spp., Azospirillum spp. та інші. Цікавим фактом, що було виявлено в результаті цієї статті стало те, що деякі мікроорганізми можуть виявляти позитивну дію на рослину-госоподаря не лише в одному напрямку як наприклад, Pseudomonas fluorescens.

Effect of biofertilizers with various levels of inorganic nutrients on growth and yield of black cumin (Nigella sativa L.) var. Azad Kalonji

The objective of the study is to reduce the amount of inorganic fertilizers by using biofertilizers with the aim of sustainable agriculture. The field experiment was conducted at the HRS, Mondouri, BCKV, West Bengal, India during rabi season of 2019-20. The experiment consisted of 14 treatments replicated thrice, comprising of three levels inorganic fertilizers (50, 75 and 100%) of recommended NPK and three biofertilizers viz. Azospirillum lipoferum (N fixer), Bacillus megaterium (potash mobilizer) and Fraturia aurantia (K mobilizer) as soil application. The results indicated that the maximum plant height (86.06 cm) at 100 DAS, number of primary (10.66) and secondary branches (17.33), number of capsules plant-1 (25.33), number of seeds capsule-1 (97.66), test weight (3.54 g) and projected yield (538.50 kg ha-1) were recorded in 100% RDF + Azospirillum + PSB + KS. The yield was at par with 75% RDF + Azospirillum + PSB + KS (536.74 kg ha-1). Considering the economics, maximum net return (Rs. 1,08,083.74 ha-1) and B: C ratio (4.14: 1) was obtained from 75% RDF + Azospirillum + PSB + KS. These results suggested that combination of Azospirillum + PSB + KS with 75% RDF was best for optimum production of black cumin without loss in yield and reduction of 25% of inorganic fertilizers through application of biofertilizers and environmental pollution to some extent.

Effects of iron and PGPR on antioxidant status and some physiological traits of triticale under different irrigation levels

A factorial experiment was conducted to study the effects of iron and plant growth promoting rhizobacteria (PGPR) on antioxidant status and some physiological traits of triticale under different irrigation levels. Experimental factors were included irrigation in three levels [(i) normal irrigation (I0) as control; (ii) moderate water limitation (I1) and (iii) severe water limitation (I2)]. Three PGPR levels [(i) no PGPR (P0), (ii) Psedomunas putida (P1), (iii) Azospirillum lipoferum (P2)] and three nano iron oxide levels [(i) without nano iron oxide (F0) as control, (ii) application of 0.3 (F1) and (iii) 0.6 (F2) g/l)]. Results showed that water limitation decreased chlorophyll content, relative water content and grain yield of triticale. Whereas, electrical conductivity, proline content and the activity of catalase (CAT), peroxidase (POD), polyphenol oxidase (PPO) enzymes increased. However, inoculation of plants with PGPR and iron application improved these traits under water limitation condition and normal irrigation. Based on the results, it was concluded that the application of PGPR and iron can be a proper tool for increasing triticale yield under water limitation condition.

Biofilms of Azospirillum brasilense and Azospirillum lipoferum and their resistance to abiotic stresses

The biofilms of the bacteria A. brasilense and A. lipoferum are resistant to salt (over 400 mM NaCl in the medium) and temperature (up to 48° C) stresses. The nature of resistance to these stressors is determined by the type of biofilm.

EFFECT OF ADDITION OF VERMICOMPOST, BIO AND MINERAL FERTILIZER ON THE AVAILABILITY OF SOME NUTRIENTS IN SOIL AND POTATO YIELD

A nitrogenous bio-fertilizer comibination was prepared contain Azospirillum lipoferum, and Azotobacter chroococcum bacteria. A phosphate bio-fertilizer consisting of Bacillus megaterium and Glomus mosseae fungus was also prepared. vermicompost was produced from earthworms imported from Iran and others isolated locally. A factorial experiment was carried to evaluate the effect of the interaction between these combinations and vermicompost types under levels of 0%, 25% and 50% of NPK. The results showed a significant superiority of the bio-fertilizer (nitrogen and phosphate) treatment in available nitrogen in the soil after harvest, number of tubers, yield per plant , and the total yield with 39.70 mg N kg -1, 11.03 tuber plant -1, 1367.40 g plant-1, and 43.76 Mg ha-1 respectively. While phosphate bio fertilizer treatment giving available phosphorus in the soil by 22.74 Mg P kg -1 , vermicompost produced from imported earthworms was superior in giving available phosphate in the soil with value 22.74 mg p kg -1 . While the tri interaction was superior for all studied characteristics.

Genome Sequences of Novel Azospirillum sp. Strains B21 and Sh1, Isolated from Raised Sphagnum Bogs, and Type Strains Azospirillum lipoferum 59b and Azospirillum oryzae COC8

Here, we report the genomic sequences of the novel Azospirillum sp. strains B21 and Sh1, isolated from raised bogs, along with the genome sequences of Azospirillum lipoferum 59bT, the type species of the genus, and Azospirillum oryzae COC8T, which were analyzed to get more knowledge about the genus Azospirillum.