Characterization of Bacillus altitudinis as a New Causative Agent of Bacterial Soft Rot

Abstract

A total of 67 bacterial isolates were obtained from apple and pear fruits with signs of soft rot collected from Egyptian markets. Pathogenicity tests showed that 25 isolates (37%) were pathogenic to apple and pear fruits, with considerable variation of virulence. Among these isolates, 16 (64%) were Gram‐positive, motile, spore‐forming long rods and were identified as members of the genus Bacillus based on an API test. In addition, five isolates (20%) were Gram‐negative, non‐spore‐forming, motile, oxidase and catalase‐positive short rods and were identified as members of the genus Pseudomonas. Furthermore, four isolates (16%) were Gram‐negative, non‐spore‐forming, motile, catalase‐positive and oxidase negative short rods and were identified as belonging to the genus Erwinia. All selected isolates showed a wide host range and could cause soft rot of all representative fruits and vegetables tested. The three most virulent isolates, AB4, AB6 and PB6, exhibited the highest soft rot severity on different apple and pear cultivars, and apple cv. Anna (116) was the most susceptible to infection by isolates AB4 and AB6, with soft rot severities of 63.33 and 60.67%, respectively. Also, pear cv. Le‐Conte was most susceptible to infection by isolate AB6, with a soft rot severity of 89.9%. A phylogenetic tree based on 16S rRNA gene sequences indicated that strains AB4 and AB6 were very similar to one another and also showed a similarity of 99% to Bacillus altitudinis, and strain PB6 revealed a similarity of 99% to Bacillus pumilus. To our knowledge, this is the first report of B. altitudinis as a soft rot pathogen for both apple and pear fruits.

Isolation and characterization of Bacillus altitudinis JSCX-1 as a new potential biocontrol agent against Phytophthora sojae in soybean [Glycine max (L.) Merr.]

“…altitudinis has been recently characterized as a new causative agent of bacterial soft rot on apple and pear fruit (Elbanna et al 2014). Accordingly, we tested whether the B. altitudinis JSCX-1 isolated in this study could cause soft rot on these fruit.…”

Characterization of blackleg and soft rot from potato in northern Thailand

“…Moratoğlu, Demĩrbağ, and Sezen () found that the investigated P. putida strains Ld3 and LD4 grew in 4%NaCl and at 37ºC, were positive for acid production from glucose and did not produce acid from maltose, mannitol and raffinose. Moreover, B. altitudinis was first reported as a soft rot pathogen on apple and pear fruits in Egypt; thus, the pathogen could macerate potato tubers (Elbanna et al, ).…”

“…All strains were screened for enzymes related to maceration and soft rot using the method of Chatterjee, Cui, Liu, Dumenyo, and Chatterjee (1995), Joko, Subandi, Kusumandari, Wibowo, and Priyatmojo (2014) and Elbanna et al (2014). The bacterial isolates were inoculated onto pectate lyase (hydrolysis), containing 1% polygalectoronic acid, cellulase, protease and crystal violet pectate medium (CVP) Himedia® containing 1.8% sodium polypectate (non-hydrolysis); crystal violet inhibits the growth of Gram-positive bacteria.…”

“…Recently, two novel Bacillus spp. were reported to cause soft rot of potato, B. altitudinis and B. pumilus (Babana et al, 2011;Elbanna, Elnaggar, & Bakeer, 2014). Similarly, Pseudomonas putida and Pseudomonas fluorescens were isolated from rotted potatoes (Muletet, Lalucat, & Garcia-Vades, 2010;Soleimani-Delfan, Etemadifar, Bouzari, and Emtiazi, 2012;Bhai, Kishore, Kumar, Anandaraj, & Eapan, 2012;Czajkowski, Boer, Veen, & Wolf, 2012).…”

Assaying the potential autotoxins and microbial community associated with Rehmannia glutinosa replant problems based on its ‘autotoxic circle’

“…For instance, some species of Bacillus, Pseudomonas, Acremonium and Humicola could promote plant growth due to their antagonistic activity, the production of IAA or specific substance to activate resistance for control of diseases (Dharni et al 2014;Hassan et al 2015;Khabbaz et al 2015;Wenhsiung 2009;Yang et al 2014). On the other side, some species of these genera showed negative effect on plant growth due to their broadspectrum pathogenic activity (Elbanna et al 2014;Furuya et al 2005;Iakovleva et al 2013;Racedo et al 2013;Zhang et al 2014). Additionally, the report of other plant suggested that the harmful microbes were increased with the decrease of beneficial microbes under monocultivated conditions, and the soil ecological function was affected (Lin et al 2015).…”