density, thuringiensis injected insects were investigated. B. thuringiensis is

density, pH and haemolymph proteins
of normal and B. thuringiensis injected
insects were investigated.

B.
thuringiensis is well known for its ability to
produce parasporal crystalline protein inclusions (usually referred to as
crystals), which have attracted worldwide interest for various pest management
applications because of their specific pesticidal activities (Schnepf et al., 1998). In addition to amino acid
sequence, characterization often includes bioassays against selected arthropod
(and occasionally non-arthropod) species to determine pesticidal activity. B. thuringiensis toxin specificity
database was designed to take those factors into account.

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Carlson and Kolstø (1993) reported that B. thuringiensis and B. cereus is spore forming Gram-positive
bacteria commonly found in soil and many other environmental sources. B. thuringiensis can be seen as a B. cereus that produces protein crystals
(Helgason et al., 2000); the key
characteristic of B. thuringiensis is
the production of insecticidal crystalline protein (toxin) inclusions during
the stationary phase (Schnepf et al.,
1998). Generally, the Cry toxins that
constitute the crystal inclusion are sufficient to kill infected insect larvae
of Lepidoptera, Diptera and Orthoptera. When ingested by susceptible insect
larvae, these crystal proteins are dissolved in digestive juises and activated
in the insect gut is alkaline pH. They bind to specific receptors located on
the midgut epithelial cells, forming trans-membrane pores and causing cell lysis.
In some cases, B. thuringiensis and B. cereus spores have been shown to be
involved in pathogenicity in insects, is reported by (Dubois and Dean, 1995;
Johnson and McGaughey, 1996; Li et al.,
1987). It has been suggested that the pathogenic effect of the crystal proteins
creates conditions favorable for the development of the bacteria in the gut of
weakened insect larvae (Schnepf et al.,
1998). The bacteria can then invade the haemocoel and cause Septicaemia (serious bloodstream infection). B. cereus, although commonly regarded as
a relatively pathogenic opportunist associated with diarrheal food poisoning,
has been increasingly isolated from serious and sometimes fatal cases including
non-gastrointestinal infections such as endocarditis, wound infections,
pneumonia and endophthalmitis (Beecher et
al., 1995; Drobniewski, 1993; Miller et
al., 1997). B. thuringiensis and B. cereus cells produce several
extracellular degradative enzymes such as phospholipases C, enterotoxins and
haemolysins, which are putative pathogenesis factors (Beecher et al., 1995; Drobniewski, 1993; Lereclus
et al., 1996; Agaisse et al., 1999).

The parasite spores are transmitted
to nymphs and adults through cannibalism of infected dead insects, fecal
contamination, and transovarial transfer from infected females to their
offspring (Canning, 1962). Infection of locusts by P. locustae results in impaired development, mobility, and
reproductive capacity. More importantly, infection by P. locustae inhibits aggregation of solitary locusts and induces
gregarious locusts to transform back to the solitary phase, thereby controlling
swarm outbreaks even before it causes direct mortality (Fu et al., 2010).

Knight et al, (2003) reported that the several biological control agents
have been used in India and many other parts of the world to evaluate their
potential to control the mosquito vectors. Toxins from certain strains of
bacteria, like B. thuringenesis var.
israelensis (Bti) and B. sphaericus
(Bs) are shown to be highly effective against mosquito larvae and other Diptera
spp. at very low dosage and safe to non target organisms (Lacey and Undeen,
1986; Mulla, 1990; Walton and Mulla, 1992). However, the biolarvicide
formulation from B. subtilis strain
is reported to be less effective against Anopheles
culicifacies and hardly effective against Aedes aegypti (Mittal, 2003; Wirth et al., 2005). Among the Bacillus
genus, B. subtilis produces a broad
spectrum of bioactive lipopeptides having a great potential for
biotechnological and biopharmaceutical applications such as their use as
antiviral, antibacterial, and antitumor agents, and immune-modulators (Cameotra
and Makkar, 2004). The characteristic structural element of lipopeptides is a
specific fatty acid, which is combined with an amino acid moiety. The
lipopeptide is composed of various isoforms of surfactin, fengycin and the
iturin (Vater et al., 2002).
Surfactin is the most powerful biosurfactant known till date (Cooper et al., 1989) where as iturins (pore
forming) possess antagonistic effects against a wide range of microorganisms
ranging from bacteria, fungus to yeast (Singh and Cameotra, 2004). Although
these lipopeptides exhibit insecticide activity against fruit fly, Drosophila melanogaster (Assie et al., 2002), their larvicidal activity
against mosquito vectors has never been tested. Investigated the mosquito
larvicidal activity of the cyclic lipopeptides (CLPs) secreted by B. subtilis that were isolated from
traditional fermented food (Das et al.,
2004) and a petroleum crude oil contaminated soil sample respectively. Further,
we assessed the biosafety of B. subtilis
lipopeptides on Indian major carp Labeo
rohita, a non-target aquatic organism.

Antibiotics

The antibiotics are classified into two types bactericidal (Killing
bacteria) and bacteriostatic (inhibits growth of bacteria) Examples of
bactericidal are ofloxacin, penicillin, aminoglycosides and that of
bacteriostatic are tetracycline, erythromycin, chloramphenicol etc.

density, pH and haemolymph proteins
of normal and B. thuringiensis injected
insects were investigated.

B.
thuringiensis is well known for its ability to
produce parasporal crystalline protein inclusions (usually referred to as
crystals), which have attracted worldwide interest for various pest management
applications because of their specific pesticidal activities (Schnepf et al., 1998). In addition to amino acid
sequence, characterization often includes bioassays against selected arthropod
(and occasionally non-arthropod) species to determine pesticidal activity. B. thuringiensis toxin specificity
database was designed to take those factors into account.

We Will Write a Custom Essay Specifically
For You For Only $13.90/page!


order now

Carlson and Kolstø (1993) reported that B. thuringiensis and B. cereus is spore forming Gram-positive
bacteria commonly found in soil and many other environmental sources. B. thuringiensis can be seen as a B. cereus that produces protein crystals
(Helgason et al., 2000); the key
characteristic of B. thuringiensis is
the production of insecticidal crystalline protein (toxin) inclusions during
the stationary phase (Schnepf et al.,
1998). Generally, the Cry toxins that
constitute the crystal inclusion are sufficient to kill infected insect larvae
of Lepidoptera, Diptera and Orthoptera. When ingested by susceptible insect
larvae, these crystal proteins are dissolved in digestive juises and activated
in the insect gut is alkaline pH. They bind to specific receptors located on
the midgut epithelial cells, forming trans-membrane pores and causing cell lysis.
In some cases, B. thuringiensis and B. cereus spores have been shown to be
involved in pathogenicity in insects, is reported by (Dubois and Dean, 1995;
Johnson and McGaughey, 1996; Li et al.,
1987). It has been suggested that the pathogenic effect of the crystal proteins
creates conditions favorable for the development of the bacteria in the gut of
weakened insect larvae (Schnepf et al.,
1998). The bacteria can then invade the haemocoel and cause Septicaemia (serious bloodstream infection). B. cereus, although commonly regarded as
a relatively pathogenic opportunist associated with diarrheal food poisoning,
has been increasingly isolated from serious and sometimes fatal cases including
non-gastrointestinal infections such as endocarditis, wound infections,
pneumonia and endophthalmitis (Beecher et
al., 1995; Drobniewski, 1993; Miller et
al., 1997). B. thuringiensis and B. cereus cells produce several
extracellular degradative enzymes such as phospholipases C, enterotoxins and
haemolysins, which are putative pathogenesis factors (Beecher et al., 1995; Drobniewski, 1993; Lereclus
et al., 1996; Agaisse et al., 1999).

The parasite spores are transmitted
to nymphs and adults through cannibalism of infected dead insects, fecal
contamination, and transovarial transfer from infected females to their
offspring (Canning, 1962). Infection of locusts by P. locustae results in impaired development, mobility, and
reproductive capacity. More importantly, infection by P. locustae inhibits aggregation of solitary locusts and induces
gregarious locusts to transform back to the solitary phase, thereby controlling
swarm outbreaks even before it causes direct mortality (Fu et al., 2010).

Knight et al, (2003) reported that the several biological control agents
have been used in India and many other parts of the world to evaluate their
potential to control the mosquito vectors. Toxins from certain strains of
bacteria, like B. thuringenesis var.
israelensis (Bti) and B. sphaericus
(Bs) are shown to be highly effective against mosquito larvae and other Diptera
spp. at very low dosage and safe to non target organisms (Lacey and Undeen,
1986; Mulla, 1990; Walton and Mulla, 1992). However, the biolarvicide
formulation from B. subtilis strain
is reported to be less effective against Anopheles
culicifacies and hardly effective against Aedes aegypti (Mittal, 2003; Wirth et al., 2005). Among the Bacillus
genus, B. subtilis produces a broad
spectrum of bioactive lipopeptides having a great potential for
biotechnological and biopharmaceutical applications such as their use as
antiviral, antibacterial, and antitumor agents, and immune-modulators (Cameotra
and Makkar, 2004). The characteristic structural element of lipopeptides is a
specific fatty acid, which is combined with an amino acid moiety. The
lipopeptide is composed of various isoforms of surfactin, fengycin and the
iturin (Vater et al., 2002).
Surfactin is the most powerful biosurfactant known till date (Cooper et al., 1989) where as iturins (pore
forming) possess antagonistic effects against a wide range of microorganisms
ranging from bacteria, fungus to yeast (Singh and Cameotra, 2004). Although
these lipopeptides exhibit insecticide activity against fruit fly, Drosophila melanogaster (Assie et al., 2002), their larvicidal activity
against mosquito vectors has never been tested. Investigated the mosquito
larvicidal activity of the cyclic lipopeptides (CLPs) secreted by B. subtilis that were isolated from
traditional fermented food (Das et al.,
2004) and a petroleum crude oil contaminated soil sample respectively. Further,
we assessed the biosafety of B. subtilis
lipopeptides on Indian major carp Labeo
rohita, a non-target aquatic organism.

Antibiotics

The antibiotics are classified into two types bactericidal (Killing
bacteria) and bacteriostatic (inhibits growth of bacteria) Examples of
bactericidal are ofloxacin, penicillin, aminoglycosides and that of
bacteriostatic are tetracycline, erythromycin, chloramphenicol etc.

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