Biocontrol agents

Bottiglieri M, C Keel (2006) Characterization of PhlG, a hydrolase that specifically degrades the antifungal compound diacetylphloroglucinol in the biocontrol agent Pseudomonas fluorescens CHAO. Appl Environ Microbiol 72 418-427. 

There has been considerable interest in the use of plants for bioremediation and this merits a rather extensive discussion. Plants can play an important role in bioremediation for several reasons (1) they can transport contaminants from the soil, (2) they can metabolize the contaminants after uptake, or (3) they can produce exudes that support microbial activity for degradation of the contaminants. In addition, bacteria can produce metabolites that counter the effect of toxins produced by fungi, and serve as biocontrol agents that diminish the need for the application of agrochemicals. Plant exudates play an important role in supporting the growth and activity of bacteria that carry out the degradation of contaminants in the rhizosphere and rhizoplane (the external surface of roots... 

As a dividend, bacteria are important as biocontrol agents against a number of plant pathogens. 

Biocontrol agent Antibiotic compound Phytopathogen Protected host Disease References... 

Table lists examples of known biocontrol agents, the antibiotic compounds associated with control of disease-causing agent, protected host, and references. 

Many rhizobacteria are classified as chitinolytic and, for example, Serratki marsescens, which excretes chitinase, was found to be an effective biocontrol agent against Sclerotium rolfsii (135). Similarly, Aeromonas caviae was found to reduce disease caused by Rhizoctonia solani, Fusarium oxysporuin, and Sclerotium rolfsii (136). There is also evidence to support the role of P-l,3 glucanase in biocontrol of soil-borne plant pathogens (137). 

G. Defago, C. Keel, and D. Hass, Pseudonionads as biocontrol agents of diseases caused by soil-borne pathogens. Biological Control Benefits and Risks (H. M. T. Hokkanen and J. M. Lynch, eds,), Cambridge University Press, Cambridge. UK, 1995, p. 137. 

The lack of simple and reliable application systems is a major problem to be solved before the introduction of this biocontrol agent into practical control strategies. Mixing fungal chlamydospores into a feed supplement was used in most plot and field studies as an application system (Larsen, 2000). Incorporation into various types of feed blocks or mineral licks, as well as slow-release devices, may also become feasible (Thamsborg et al., 1999 Chandrawathani et al., 2003). 

British Crop Protection Council (2004). The Manual of Biocontrol Agents, L.G. Copping (ed.), British Crop Protection Council, Alton, Hampshire, UK, 758 pp. 

Yao HJ and Tian SP. 2005. Effects of biocontrol agent and methyl jasmonate on postharvest diseases of peach fruit and the possible mechanisms involved. J Appl Microbiol 98 941-950. 

The use of nematodes as a biocontrol agent has been developed in the past 2 decades. Proper use of these bioagents on experimental scale has proved superbly successful in both short- and long-term pest suppressions. Crop insect pests are one... 

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