here it expresses the importance of protease enzyme in soil health and decomposing impact on other microbes and soil mineral recycling

1. PROTEASE
The main Nitrogen mineralizer & catalyzer
of hydrolysis of proteins in soil
BY
A.A.J.K. Eranga
20282 - PDN

2. What is Soil Enzyme?
Soils are enzymically active component and have origin of plant, animal
and microbial, and collectively their activities express the metabolic status
of soils at a given time. Ladd J.N. (1985)
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• In generally, a enzyme plays a vital role in maintaining soil ecology, physical &
chemical properties, fertility, and soil health.

3. WHAT IS PROTEASE ENZYME?
• Protease in soil, Involved in the initial hydrolysis of protein components of
organic nitrogen to simple amino acids.
• Hydrolytic degradation of proteins is an important step in the nitrogen
cycle. Proteases in soils hydrolyze not only added proteins but also native
soil added proteins
• Large portion of the nitrogen (N) in soil is in the form of proteinaceous material
& nitrogenous compounds in mineral soils are present in an organic form.
• Proteinaceous material’s are the main source of “N” in soil organic matter.
Use of this nitrogen limited by breakdown of proteins into peptides & free
amino acids.
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National Center for Biotechnology
Information
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Luang-In V, et al 2019

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Luang-In V, et al 2019

8. How protease add into soil
• Proteases are widely distributed in microbes, plants and animals.
• Originated from animals, plants and microorganisms, while the
presence in soils of enzymes derived directly and specifically from
animal and plant sources.
• soil enzymes are derived primarily from microorganisms (Ladd, 1978)
• And it generally associated with both organic & inorganic colloids.
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9. • Protease playing a vital role in the use of Nitrogen from proteinaceous
materials.
• Also, catalyze the “High molecular weight (HMW) peptidic nitrogen
breakdowns into low molecular weight organic compounds such as
oligopeptides and amino acids”.
• Protease activities have been reported to occur partly in soil as a humo-
carbohydrate complex.
• And, usually have a wide substrate-specificity and influenced on
degrading most nonstructural proteins
WHAT IS PROTEASE ENZYME DO?
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10. • Due to the abundance of proteins and peptides in soil, proteases likely
supply a large part of the bioavailable N.
• Protease activities are affected by several biotic and abiotic factors. For
example, low concentrations of neutralized soil humic acids inhibit some
and stimulate other protease activity by mechanisms involving primarily
humic acid carboxyl groups, which is,
• Highly dynamic and easily available pool of organic N in soils with half-life
times of minutes to hours.
• In decomposing litter and in soils, protein depolymerization rates by
far exceed those of inorganic N processes such as organic N
mineralization and nitrification
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12. • Extracellular enzymes acting as a tools that microbes use to fulfill their roles
as material recyclers in the global carbon and nutrient cycles.
• The extracellular protease is indicative of the biological capacity of soil & plays
an important role in the ecology of microorganisms in the ecosystem & play
important pathogenic roles in suppressing some nematodes in the soil
• Plant roots can also release extracellular proteases into the soil and, contain a
wide range of intracellular proteases too. These are having following functions,
1. Enhancing availability of N for nutrition
2. Defense against plant pathogenic organisms
3. Root cell expansion
4. Regulation of proteins, peptides in response to
developmental & environmental reasons
Protease enzyme as extracellular component,
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13. • Soils parent materials differentiated in their optimal pH for protease activity and
in their relative rates of attack on different proteins. And,
• Factors that influence on soil protease concentration are, soil incubation
temperature, moisture & salt content, and drying, on the production and stability
of neutral and alkaline proteases in soils, Ladd J.N. and butler J.H.A(1972)
• Land use related N inputs by synthetic fertilizers or manure may further
suppress (inorganic N) or stimulate (organic N) soil protease production
Factors affecting on soil protease concentration
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14. • Production & potential activity of extracellular proteases is therefore driven by substrate
supply, litter quality, consequently microbial C and N demands
• Microbial C limitation due to reduced litter input in cropland soils promotes organic N
mineralization as microbes decompose available organic N compounds to meet their energy
demands & excrete excess N as Ammonium ions (Mooshammer et al., 2014). And,
• Specially, the
• Soil protease activities were increased in, Treatment of soils with metal-contaminated sewage
sludge, effluents from cotton ginning mills, and pig slurry. And,
• Soil protease activities were decreased in, soils treated with herbicides, insecticides, organic
matter, crude oils, and chlorothalonil compounds (Naga Raju M. et al,2017)
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Factors affecting on soil protease concentration cont.,

15. What Limits the protease concentration in soil?
• Soil temperature
• C:N ratio
• Soil moisture content
• Pesticides/ Herbicides availability
• Heavy metals in soil
• Bioavailable nitrogen content
• Soil pH
• Soil texture
• Organic matter concentration
• Land use patterns & Crop type etc.,
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16. References
1. Das, Shonkor & Varma, Ajit. (1970). Role of Enzymes in Maintaining Soil Health. 10.1007/978-3-642-14225-3_2.
2. Geisseler, D., & Horwath, W. R. (2008). Regulation of extracellular protease activity in soil in response to different sources
and concentrations of nitrogen and carbon. Soil biology and biochemistry, 40(12), 3040-3048.
3. Greenfield, L.M., Hill, P.W., Paterson, E. et al. Do plants use root-derived proteases to promote the uptake of soil organic
nitrogen?. Plant Soil 456, 355–367 (2020).
4. Ladd, J. N., & Butler, J. H. A. (1972). Short-term assays of soil proteolytic enzyme activities using proteins and dipeptide
derivatives as substrates. Soil biology and biochemistry, 4(1), 19-30.
5. Ladd, J.N., Jackson, R.B., 1982. Biochemistry of ammonification. In: Stevenson, F.J. (Ed.), Nitrogen in Agricultural Soils.
American Society of Agronomy, Crop Science Society of America, Soil Science Society of America, Madison, WI, pp. 173–
228.
6. Ladd, J. N. ( 1978): Origin and range of enzymes in soil. In Soil enzymes. ed. Burns, R.O., 51 -96.
7. Luang-In V, Yotchaisarn M, Saengha W, Udomwong P, Deeseenthum S, Maneewan K. Protease-Producing Bacteria from
Soil in Nasinuan Community Forest, Mahasarakham Province, Thailand. Biomed Pharmacol J 2019;12(2).
8. Naga Raju M., Golla N., Vengatampalli R. (2017) Soil Protease. In: Soil Enzymes. SpringerBriefs in Environmental Science.
Springer, Cham. https://doi.org/10.1007/978-3-319-42655-6_5
9. Rani, Kirti & Rana, Rachita & Datt, Sanchi. (2012). Review on latest overview of proteases. International Journal of current
life sciences. 2. 12-18.
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