1. Microbial Biodeterioration of Material and it’s Control
Arish Daud
Musawer Ali
Sagheer Ahmed
Anil Yousaf Masih
Danish Gul

2. Biodeterioration
Bio-life
Deterioration- destruction, impairment
H. J. Hueck gave the first definition in a paper in 1965:
“any undesirable change in the properties of a material caused by the vital activities of an organism”
Text book defines it as “any undesirable change occurring in a natural or processed material of economic importance, brought about by the activities of living organisms whether plants, animals or, microorganisms”

3. Natural Material Processed Material Animal products (bone, fur etc.)
Plant products (wood, cotton etc.)
Stored unprocessed foodstuffs (grain, potatoes, fruits etc.)
Stone
Processed Material
Building materials (brick, concrete and mortar)
Cellulosic materials (chipboard, paper and card)
Petrochemical products (fuels and lubricants),
Glass,
Metals,
Paints
Pharmaceuticals,
Cosmetics and toiletries,
Other products such as microchips.

4. Biodeterioration vs. Biodegradation
Biodegradation is also impairing things by living organisms, so does that mean both terms have same meaning?
NO!
Biodegradation-
positive aspects of microbial activities
Biodeterioration
negative aspects of microbial activities
Depends on the location of microbial activity

5. Wet Rot decaying ceiling
Biodegradation
Biodeterioration
Fallen tree decaying
Wet Rot decaying ceiling

6. Biodeterioration of solid materials
solid materials starts
with formation
of a biofilm

7. Factors that cause Damage
Fungal hyphae growing through walls
Microbial mass causing breakage of pipes
Mechanical/Physical Damage
Utilizing the material as a carbon or energy source
Chemical/Biochemical Processes Damage
Aka aesthetic biodeterioration
Simply present on a surface,
feeding on the top layer
Do not cause physical damage
Soiling/Fouling

8. Biodeterioration Cont…
Biodeteriogenesis functions like a disease
Has three phases:
Infection/Contamination
Incubation
Manifestation (Symptoms start appearing)
Economic aspects
Cost of prevention (physical-cooling or chemical-preservatives etc.)
Material replacement
Restoration

9. Biodeterioration of Stored Plant Food Material
Anil Yousaf Masih

10. Non Food Animal Products
Sagheer Ahmad Malik

11. Non Food Animal Products
Hides(animal skin treated for human use)
Leather
Stone and related building materials
Cellulosic materials

12. Leather Contain fatty and proteinaceous debris
Could be degraded by proteolytic and lipolytic enzymes by micro-organisms
To avoid this biocides are used

13. Steps for leather production
Soaking in water
Susceptible to attack by bacteria B. subtilis etc
Enzyme are secreted at this stage.
Active even after the death of micro-organisms
Liming, deliming and then tanning
Drying
80% humidity favours micro-organisms growth
Fungi is primary biodeteriogens
Bacteria are usually secondary colonizers

14. Wool, fur and feathers composed of cystine-rich protein keratin
Losses are because of keratinophilic fungi and certain bacteria
The damages are pigmentation, odour production and loss of tensile strength
incorporation of biocides during processing prevents from the problem

15. Stone and related building materials
prone to microbial attack mainly Algae, cyanobacteria, fungi or lichens.
Causes soiling, excessive expansion, widening of cracks
excretion of corrosive metabolites
Several organic acids solubilize calcium carbonate
oxalic and citric acid solubilize
silicates

16. Continue
Nitrifying bacteria, may also cause damage by solubilizing calcium-based rock, as their oxidation of ammonia to nitrate leads to the formation of a relatively soluble salt, calcium nitrate.
Problems can be handled by frequent painting, or cleaning with biocidal washes of bleach, phenolics.

17. Cellulosic materials wood, card, paper and plant fiber textiles
susceptible to fungal attack, some bacteria, notably Cellulomonas and Cellvibrio specie.
Enzymes are cellulase, a complex of several enzymes including exo-b-1,4-glucanase, endo-b-1,4-glucanase and b-glucosidase, and hemicellulases
Damage ranges from loss of quality to major reductions in strength.
They do not spread beyond the damp areas and are far easier to treat by biocides

18. Degradation of Metals
Musawar Ali

19. Degradation of Metals
There are three main routes of microbial corrosion of metals.
Concentration of cells
Release of corrosive metabolic products
Removal of cathodic hydrogen by sulphate reducing bacteria

20. Microbial concentration cells
As a result of oxygen gradient
Microbes on borders have access to more oxygen so they become cathodic
Oxygen limited centre becomes anodic
Metal in the oxygen deficient portion loses electrons and becomes positively charged and reacts with OH- ions to form insoluble metal hydroxide.

21. Corrosive metabolic products
Microorganisms produce organic and inorganic acids cause metal corrosion
examples:
Sulphur oxidizers produce highly corrosive sulphuric acid which degrades fuel tanks.
Sulphate reducing bacteria produce hydrogen sulphide which can cause sulphide stress cracking. Susceptible alloys, especially steels, react with hydrogen sulfide, forming metal sulfides and atomic hydrogen as a result of corrosion.

22. Plastic degradation
Plastics are polymeric materials that include polyethylenes, polystyrene, polyvinylchloride and polyesters.
Plastic material are largely resistant to microbial attack but the other materials added to the plastic are suseptible to microbial attack.
initially the microbes metabolize these additives and form a surface biofilm as a result of which plastic becomes fragile and discolored.

23. Biodeterioration of Cosmetics and Pharmaceuticals
Arish Daud

24. Pharmaceutical product classification
Non-sterile: solids (tablets, capsules and powders),
liquids (suspensions and syrups), creams and lotions;
Sterile: injectables (parenterals), both single dose and multidose drugs, intravenous infusions, etc., along with products for use in and around the eye area, including drops, lotions, ointment, washes and contact lens cleaning solutions.

25. Cosmetics preparation and microbial growth
Reasons for Unsaleable of products
The presence of low levels of acutely pathogenic microorganisms or higher levels of opportunistic pathogens.
Contamination with toxic microbial metabolites that can persist even when the producer microorganisms are
dead or removed.

26. The occurrence of detectable physical and/or chemical changes.
Loss of function of the active ingredient(s).
The presence of pathogens or potential pathogens
Application of spoilage products on healthy people and hospital patients

27. Presence of Microbial toxins
Relation to injectable drugs
Myotoxins and Endotoxins mainly (pyrogens)
Use of ultrapure water for injections

28. Chemical and physicochemical changes
Change depends upon chemical structure of ingredients and physiochemical nature of product
Initiation of attack by pathogens to cause change of nature and structure of product
Oils and fats are particularly susceptible to microbial attack

29. Loss of function of the active ingredient
The active ingredient is often present at relatively low Concentrations
Active ingredient may be therapeutic or antimicrobial agents, and in cosmetics and toiletries they are mostlydetergents,coloring agents
Bacterial species attack the detergent in cosmetics and toileteries are Pseudomonas, Citrobacter and Aerobacter species

30. Factors influencing microbial spoilage
Microbial growth is determined by nutrient status of the product formulation, pH, oxygen concentration, water activity, temperature and the efficacy of the oxygen concentration of the preservative system employed

31. Moisture content of a product
Redox potential, the oxidation–reduction balance
The pH of a product obviously influences the range of microorganisms that will grow
Package design also influences the susceptibility of a product to Biodeterioration

32. Assessment of microbial contamination
(microbiological quality control)
Microbial quality control is conducted to:
monitor microbial contamination of raw materials;
monitor and confirm the efficacy of operations such as sterilization;
control the danger from pathogenic microorganisms by confirming their absence

33. Verify the expected storage life and provide an estimate of perishability
Sensitive analytical tests are available for the detection of very low levels of mycotoxins.
Amoebocyte lysate assay
Very sensitive and can detect as little as g/ml.

34. Detection of microbial enzymes
is often important
Other tests that may be performed on the products are ‘challenge tests’ ( utilization of Biodeteriogens Pseudomonas aeruginosa (Gram-negative), Staphylococcus
aureus (Gram-positive), Candida albicans (yeast)
and Aspergillus niger (filamentous fungus)

35. Preservatives Which one to add? How much to add?
Chemicals or substances that preserves or protects the substance added to.
Aim of using preservatives:
Kill or inhibit growth of microbes
Which one to add?
The least toxic that will do the Job!
How much to add?
As little as possible
BUT! Don’t
Underdose-could cause development of resistance
Overdose- less economical, and could be toxic

36. What’s a good preservative like?
Broad Spectrum
Free from toxicity, irritancy and allergenicity,
Stable,
Compatible with all other formulation ingredients
Free from odor and flavor.
Has no effect on chemical or physical properties of the product.

37. Cont… Final Choice of Preservative for a substance depends on:
Activity spectrum
Solubility
Stability
Volatility
Toxicity
Color,
Odor,
Irritancy,
Taste,
And especially pH:
Preservatives have a small range of pH to work on.

38. Availability of Preservative in the Product
Not all the preservative present in the product is available for the “preservation”
The unavailable preservative could exhibit allergenecity or toxicity.
Multiple factors for this unavailability
Basic factor
Most of the Cosmetic products are multiphase systems
Are in the form of emulsions

39. Total Preservative “Active available preservative
Adsorbed to Closure and Container
Interacts with formulation ingredient
Adsorbed to solid particulate material
Partition into oil phase
Aqueous phase preservative
Inactive pH effect, etc.
Degraded
“Active available preservative

40. Preservatives for Cosmetics and Pharmaceuticals
Some of the Preservatives are:
Alcohols
Widely used disinfectant and antiseptic
Ineffective against endospores
50-70% ethanol denatures proteins and solubilize lipids
Formaldehyde
Highly reactive
Reacts with NH2, SH and COOH group
Possibly carcinogenic
Formaldehyde donors, like Germall 115-imidazolidinyl urea now preferred
Less carcinogenic

41. Cont… Quaternary Ammonium Cpds. Silver nitrate Surfactants
Skin antiseptics and disinfectants
Preservative for ophthalmic preparations, like eye drops, contact lens solutions
Activity enhanced by EDTA
Less active in presence of organic cpds.
Silver nitrate
General antiseptic
Used in pharmaceutical products for the eyes

42. When different preservatives are mixed up…!
Great benefits have been gained:
Increase in activity spectrum
Reduced irritancy and toxicity (low level of each is used)
Decreased chance of development of resistant microorganisms
Synergistic preservative effects
Prolongation of preservative action
Compensation for physicochemical limitations.

43. Biodeterioration Testing
Testing of materials for resistance to biodeterioration and also testing for the efficacy of biocidal treatments
Two ways to do it:
Soil Burial tests
Material is buried in the soil for some time,
Later removed and checked for changes in color, tensile strength, loss of mass etc. OR
Specifically challenged with a known biodeteriogen:
Provide favorable conditions like pH, temperature, humidity etc.
After some period of incubation test the material for changes and loss in different properties.