From Lab to Market
Bacillus thuringiensis: as a common
bioinsecticide
BY
Prof. Dr. Salah Mostafa
Microbial Molecular Biology Dep.
AGERI
Introduction
There is a worldwide concern regarding the indiscriminate use of pesticides and
their negative impacts, showing the need to develop environmentally safer
methods for pest control. The developing countries are interested in the
implementation of integrated pest management (IPM) programs. As part of such
programs, the use of microorganisms has shown some remarkable successes,
including bacteria, fungi, and viruses as commercial products. Among the
microorganisms, many spore-forming bacteria stands out as they are a source of
distinct promissory molecules with insecticidal activities. Bacillus thuringiensis is
the most important for its bioinsecticide activity. The insecticides based on
entomopathogenous are most often very specific and show low or no toxicity to
vertebrates and beneficial insects. Until the end of the twentieth century, the use
of bioinsecticides reached 1–2% of the total insecticidal market (plant protection
uses).
Bacillus thuringiensis (Bt) as
Successful Bio-insecticide
What is Bacillus thuringiensis?
Bt is a Gram-positive, spore-forming, facultative bacterium, about 0.5–1.0×2–5 µm in size.
There are over 100 subspecies and varieties divided into 70 serotypes, based on flagellar H antigens.
In nature, Bt has been reported from all continents.
It has been isolated from diseased insects, from the soil, from granary dust, and from the leaf surface
of many plants.
The insecticidal properties of Bt were recognized many years before the bacterium was identified, with
some accounts suggesting that Bt spores may have already been in use in ancient Egypt. In the
modern era, the bacterium was isolated in 1901 by the Japanese biologist Shigetane Ishiwatari during
an investigation into wilt disease in silk worms, and he named it Bacillus sotto.
Host specificity.
Vegetative and sporulated cells
Mode of action
(1) Ingestion of bacteria
(2) Solubilization of the crystals
(3) Activation protein
(4) Binding of proteins to the receptors membrane
(5) Pore formation and cell lise
Steps of production Bacillus thuringiensis from lab to
market
• Lab level
• Pilot level
• Industrial level
• Registration and field trails
• Marketing
Lab level
• Collection of samples
• Isolation of Bt
• Identification
• Grown of selected bacterial isolates on lab media and
fermentation media using shake flasks
• Study the different parameters that effect bacterial growth
• fermentation process optimization using cheap raw materials
• Study the insecticidal activity, using bioassay
• Storage and maintenance of bacterial srains
Pilot fermenters
Pilot level
Fermentation methods
Cultivation of entomopathogenic bacteria are carried out in batch or fed batch.
In a typical batch fermentation process, cultures of Bt is characterized by the following
morphological and physiological variations:
a)Vegetative growth stage, with the occurrence of exponential phase, presence of isolated
cells, in pairs and in chains, with uniform size and high mobility.
b)Transition to sporulation, with decreased growth rate and presence of shorter and
isolated cells without motility.
c)Stage of sporulation; d) Stage of spore maturation and cell lysis.
In Bt cultures is observed a linear growth phase after exponential growth phase, with
rapid drop in pH. In the stage of sporulation, there is a tendency to cells flocculation
Industrial level
Fermentation techniques for Mass Production
After the growth and sporulation processes have been thoroughly investigated
and tested at laboratory leveland pilot, mass production of Bt can be undertaken
on an industrial scale with various raw materials.
The standard method of production of microorganisms is the process of
fermentation.
There are many types of fermentation; the two most common are submerged and
solid.
For optimal growth of Bt, important factors are pH, temperature and oxygen.
It is possible to control these parameters in fermenters. Hence Bt is traditionally
produced in liquid media in large-capacity industrial fermenters, employing the
method of submerged or deep-tank fermentation, which is as the name implies
growth of microorganism in a fully liquid system.
Formulation of Bacillus thuringiensis
Formulation has always been regarded as the most important
part of production in the microbial pesticides industry and one of
the main concerns of producers. There are three common Bt
formulations in the agricultural marketplace today: the WP, the
SC in either an oil base or aqueous base, and the WG.
Registration of Bacillus
thuringiensis in Egypt
Agricultural pesticide committee
Field trials
Safety of the product
Registration No. Crop Name. Pest Name
Field trails
• B. t. works essentially as a stomach poison and therefore needs to be
ingested by the target insect. Any application technique must
therefore deliver the B. t. to the region of the crop where the insect
feeds. This is often not an easy task.
• By far, the most widely employed method of delivering pesticides to
the target is through spray application. Within this field there has
been a lot of research over several years, directed of course toward
the application of chemical insecticides. B. t. can be regarded as a
particulate stomach poison and thus much of the technology for
application of conventional insecticides can be employed for B. t.
Other relatively high volume sprayers include the motorised hose
sprayer used in Egypt. Typically this delivers 400-600 liters/ha.
More than 40 types of Lepidoptera pests in cotton, corn, rice, vegetables, fruits, tea,
hemp, tobacco, and forest have been tested for control effectiveness.
Marketing of Bioinsectiside based
on Bacillus thuringiensis
At present B. t. accounts for perhaps 80-90% of the total world microbial insecticide
market of about $ 100 million (Carlton, Gawron-Burke and Johnson,
1990). pesticides market value, which was USD 1.80 billion in 2020 will climb up to
USD 5.94 billion by the year 2028
Global Bacillus Thuringiensis Bio Pesticides Market, By Mode of Application (Seed
Treatment, Foliar Application and Other Applications), Crop Type (Grains and
Cereals, Pulses and Oilseeds, Commercial Crops, Fruits and Vegetables and Other
Crop Types), Formulation (Dry and Liquid), Country (U.S., Canada, Mexico,
Germany, Poland, Ireland, Italy, U.K., France, Spain, Netherland, Belgium,
Switzerland, Turkey, Russia, Rest of Europe, Japan, China, India, South Korea, New
Zealand, Vietnam, Australia, Singapore, Malaysia, Thailand, Indonesia, Philippines,
Rest of Asia-Pacific, Brazil, Argentina, Chile, Rest of South America, UAE, Saudi
Arabia, Egypt, Kuwait, South Africa, Rest of Middle East and Africa) Industry Trends
and Forecast to 2028
Bt products
AGERI, Agerin Plant protection, protecteor
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