Saran's Learn Microbiology

BIOCONTROL AGENT – Trichoderma sp. General Characteristics of Trichoderma sp. Trichoderma  is a genus of fungi in the family Hypocreaceae, commonly one of the rhizosphere inhabitants. Trichoderma sp. is the avirulent plant symbiont fungus which acts as an antagonistic against many plant pathogenic fungi and offers protection from phytopathogenic plant diseases. The discovery of  Trichoderma  spp. as natural decomposition agent and biological agent of bioremediation has been reported by several studies. Trichoderma sp. is highly involved in the production of Transgenic plants. Trichoderma  spp. have great potential against soil borne pathogens, and it may be able to replace chemical pesticides in the near future. The difficulties encountered during the identification of  Trichoderma  isolates at the species level become more significant because of the morphological differences are rare and hard to observe. Commonly, biological control agents may not affect non-target organisms. Unfor

 BIOCONTROL AGENT - Pseudomonas fluorescens General Characteristics of Pseudomonas fluorescens Gram’s classification – Gram negative Shape – Rod shape Arrangement – Single in arrangement Size – Measures approximately 0.5 μ m in width and 2.0 - 2.5 μ m in length Family – Pseudomonadaceae Motility – Motile (due to presence of several Polar flagella) Capsule – Absent Endospores – Absent Respiration – Obligate aerobe. Optimum Temperature – 25 °C to 30 °C. Optimum pH – 7.0 Pseudomonas fluorescens secretes a soluble Greenish fluorescent pigment called Fluorescein, particularly under conditions of low iron availability. Pseudomonas fluorescens can able to produce Fluorescent pigment on King’s B Medium and shows positive reaction for Gelatin liquefaction, Catalase test, Oxidase test, Starch hydrolysis, Levan formation from sucrose, Citrate utilization, etc. Pseudomonas

BIOCONTROL AGENT – Bacillus subtilis General Characteristics of Bacillus subtilis Gram’s classification – Gram positive Shape – Rod shape Arrangement - Single, pair or chains Size – Measures 4 –10 μ m long and 0.25 – 1.0 μ m in diameter Family – Bacillaceae Motility – Motile (Swarming motility) Capsule – Absent Endospores – Present (Central spores) Respiration – Facultative anaerobic. Optimum Temperature – Grow in the mesophilic temperature range. The optimal temperature is 25 °C to 35 °C. Optimum pH – 8.0 Bacillus subtilis is also called as Hay Bacillus or Grass Bacillus. The word Bacillus refers to the shape of the bacteria (rod-shaped) and subtilis means slim, slender. Bacillus subtilis  bacteria secrete enzymes such as Amylase, Protease, Pullulanase, Chitinase, Xylanase and Lipase. These enzymes are produced commercially and this enzyme production

ENTOMOPATHOGENIC FUNGI – Lecanicillium lecanii General Characteristics of Lecanicillium lecanii Lecanicillium lecanii (Order – Hypocreales; Family - Cordycipitaceae) commonly known as “White Halo Fungus” is known to cause Mycosisin insects. Lecanicillium lecanii  is now an approved name of an Entomopathogenic fungus species, that was previously widely known as  Verticillium lecanii. Lecanicillium lecanii acts as an insect biopesticide which commonly used in pest management. Lecanicillium lecanii are important entomopathogenic fungi ubiquitously distributed in soils, although these fungi are mainly isolated from insects. The entomopathogenic fungus  Lecanicillium lecanii  has been developed as biopesticides and used widely for biological control of several insects in agricultural practice. Due to the lack of isolation/count methods for  Lecanicillium lecanii  in soil, the persistence of this fungus in soil appears to have attracted no attention. Target Insects of Lecanicillium lecani