Division of City SchoolsCity of Mandaluyong Science High SchoolE. Pantaleon St., Hulo, Mandaluyong City

CHITIN FROM SHRIMP SHELLS AS SOIL CONDITIONER

A Science Investigatory Project submitted to

Mr. Benjamin Ola

Research Adviser

In Partial Fulfillment for the Requirements in Research II

Prepared by:

Diano, Jessieca B.

Deynata, James Dean I.

Escabusa, John Vincent D.

Gacura, Mathew A.

Magno, Ron Matthew C.

Neria, Khyle Tim A.

Acknowledgement

First, we would like to thank God for his gift of knowledge, patience and perseverance. Next, the

researchers would like to extend their gratitude to Mr. Benjamin G. Ola, the subject adviser, who

have patiently guided them in every part of accomplishing this investigatory project. For his

unending support and guidance throughout the whole execution of the investigation in this study.

And, For giving suggestions and tips for an effective way on how we can make our investigatory

become systematic and reliable

ABSTRACT

This investigatory project determines the possibility of making an effective soil

conditioner using chitin extracted from shrimp shells to reduce the development of Streptomyces

scabies in potatoes (Solanum tuberosum). It also aims to reduce the water pollution caused

improper disposal of shrimp shells.

The severity of infection in potatoes by Streptomyces scabies causing corky lesions

formed on tuber and root crops as well as decreasing the growth of seedlings was reduced by

application of chitin from shrimp shells as soil conditioner. The chitin was extracted from the

shrimp shells through boiling it in a dilute solution of lye, and soaking it in a dilute solution of

muriatic acid. It is also soaked in hypochloric acid for decolorization.

There were four setups of potato plants made. The first one containing 15 g of chitin, the

second setup with 20 g, the third setup with 25 g of chitin and the last setup as the controlled or

independent setup. The results of the crops from the setups were compared with its russet, pitted

and erumpent lesions. It is found out that the third setup has the least lesions and has the most

favorable appearance. Therefore the researchers conclude that the chitin can be extracted from

shrimp shells and it can help reduce the infection of Streptomyces Scabies in potato plants.

CHAPTER I

INTRODUCTION

The potato is a starchy, tuberous crop from the perennial Solanum tuberosum of

the Solanaceae family. The potato was first domesticated in the region of modern-day

southern Peru and extreme northwestern Bolivia between 8000 and 5000 BCE. It has since

spread around the world and become a staple crop in many countries. Today, the demand for

potato is increasing rapidly. During the past twenty years, the production of potatoes had

increased more than two times in rich countries. Production of potato is limited due to the

unavailability of disease free plant materials and disease reduction procedures in planting the

potatoes.

Shrimp shell wastes were also becoming one of the problems in our environment. After meals,

people threw wastes of shrimp shells into trashes which later on, go into our oceans. The shrimp

shells were now considered as one of the water pollutants in our oceans. It had been a contributor

in the destruction of the marine habitat. Instead of being thrown into the water, shrimp shells

were being studied as an alternative soil conditioner because shrimp shells contain chitin.

Chitin is a polysaccharide found in the outer skeleton of insects, crabs, shrimps, and lobsters and

in the internal structures of other invertebrates. Chitin is composed of ß(1-4) linked units of the

amino sugar N-acetyl-glucosamine, and is the main source of production of chitosan, which is

used in a number of applications, such as a flocculating agent, a wound healing agent, a sizing

and strengthening agent for paper, and a delivery vehicle for pharmaceuticals and genes.

Background of the Study

Potato (Solanum tuberosum)  is the third most important food crop in the world after rice and

wheat in terms of human consumption. More than a billion people worldwide eat potato, and

global total crop Production exceeds 300 million metric tons. But there’s a problem in the skin of

these plants, it can be easily infected by some kinds of fungi. One of these is the common scab of

potatoes, a soil-borne disease which is caused by the bacteria-like organism Streptomyces

scabies. In the search of preventing these kinds of diseases, the researchers had discovered a way

to reduce the development of Streptomyces Scabies in potato plants.

Most of us recognize that the shrimp shells are often removed before cooking or serving. Instead

of disposing these, the researchers found out that their shells contain a natural fiber called chitin

which has a potential in agriculture with regard to controlling plant diseases They were reported

to be active against viruses, bacteria and other pests. 

Recent studies have shown that shrimp have 25 to 35 percent of chitin in its shells. The

researchers then decided to extract chitin from the shrimp shells. There are several treatments

such as temperature, duration, concentration of the chemicals, concentration and size of the

crushed shells. Shell also contains lipids and pigments as a decolorizing is needed which can be

done by soaking in organic solvents or in a very dilute solution of sodium hypochlorite. 

Statement of the Problem

1. Is it possible to extract chitin from shrimp shell?

2. Is it possible to use chitin from shrimp shells as soil conditioner?

3. Does the use of shrimp shells as soil conditioner prevent infection from Streptomyces

scabies in potatoes?

Significance of the Study

This study was conducted to reduce the Streptomyces scabies with the use of extracted chitin

from the shrimp shells. The researchers believe that the problem regarding the infection of potato

plants could be lessened by the research proposal.

Streptomyces scabies or Streptomyces scabiei is a streptomycete bacterium species found in soils

around the world. Unlike most of the 500 or so Streptomyces species it is a plant

pathogen causing corky lesions to form on tuber and root crops as well as decreasing the growth

of seedlings. Along with other closely related species it causes the potato disease common scab,

which is an economically important disease in many potato growing areas.This organism attacks

the stems, stolons and roots of the potato, and more importantly, young, rapidly growing tubers,

stimulating the growth of unsightly corky tissue. A severe infection can reduce the marketable

yield and can damage the eyes of seed potatoes. It can also greatly reduce the market value of the

crop. 

With this study, the researchers can make use of disposable shrimp shells and lessen the bacteria

that attack the skin of the potato plant. It can also help in yielding of more crops and a better

quality of plants.

Scope and Limitation

The duration of this period is between the months of October and December 2012. The focus of

the investigatory project is the extraction of shrimp shells as a soil condition that aims to reduce

Streptomyces Scabies. The purpose of this study is to benefit from waste materials such as the

shrimp shells that are usually taken off. The limitation of this study is that there is a limited

percent of chtin in shrimp shells, so a large amount of shrimps is needed to conduct the research.

It also takes a lot of time for the potato plant to sprout.

Definition of Terms

Chitin - A polymer of nitrogen-containing polysaccharide rendering a tough, protective covering

or structural support in certain organisms.

Demineralization - the process of removing minerals, in the form of mineral ions

Potato- a starchy, tuberous crop from the perennial Solanum tuberosum of the Solanaceae family

(also known as the nightshades).

Streptomyces scabies or Streptomyces scabiei - A streptomycete bacterium species found in

soils around the world; it is a plant pathogen causing corky lesions to form on tuber and root

crops as well as decreasing the growth of seedlings

Soil Conditioner - A product which is added to soil to improve the soil’s physical qualities,

especially its ability to provide nutrition for plants. 

Deproteinization - the process of removing protein

Review of Related Literature

A study of the complete genome sequence of Streptomyces scabies 87.22, a common causative

agent of scab disease of tubers including potato (Solanum tuberosum), is described. This work

includes annotation of the genome and in-depth description of gene clusters likely to encode

biosynthetic pathways for complex natural products and not also found in either “Streptomyces

coelicolor” A3(2) or Streptomyces avermitilis MA-4680. Twenty-eight gene clusters were

identified as likely to encode enzymes for the biosynthesis of complex natural products.

Substances predicted by this work, not previously known to be made by S. scabies 87.22, were

confirmed by collaborators as products - desferrioxamines, germicidins, and hopene. Of the

clusters identified, fourteen gene clusters are not conserved in the other two streptomycete

genome sequences for which comparisons have been undertaken. The Streptomyces genus is a

reservoir of producer organisms from which many complex natural products of therapeutic

importance have been isolated. These findings suggest that the cargo of cryptic and silent gene

clusters amongst other members of this genus may add significantly to previous estimates of

undiscovered bioactive natural products. Methods developed in this work could enable other

researchers to rapidly identify gene clusters likely to encode enzymes involved in biosynthesis of

complex natural products from complete genome sequences. De-replication is a problem for

approaches to drug discovery based on activity screening and isolation of wild producer

organisms. Computational methods in this work allow rapid de-replication of gene clusters

following sequencing which may lead to discovery of many new natural products with

therapeutic benefit. Sequences predicted to be involved in scab disease pathogenicity are not

found in only one ‘pathogenicity island’ location as expected, but at several loci. Two possible

mechanisms were identified from sequence data which it is suggested could be involved in

regulation of pathogenicity traits: an MbtH-like protein family and an iron box sequence likely to

be triggered response to low iron conditions.

(Wellington, E. M. H. June 2009)

CAMPBELL, L. L. JUN. 8n WILLIAMS, 0. B. (1951). J. gen. Microbiol. 5, 894r905.

A Study of Chitin-decomposing Micro-organisms of Marine Origin

\BY L. L. CAMPBELL, JUN. AND 0. B. WILLIAMS

Department of Bacteriology, University of Texas, Austin, Texas, U.S.A.

SUMMARY : Twenty strains of aerobic, facultatively anaerobic, chitinoclastic

bacteria have been isolated from marine mud by enrichment cultures. Each was

able to derive its full carbon and nitrogen requirements from chitin. None was an

obligate chitinovor.

These cultures comprised four new species of Achromobacter, two new species of

Pseudomas, one new species of Flavobacterium and one new species of Micrococcus.

Detailed descriptions for each species are appended.

Each organism was able to liberate ammonia and reducing sugar from the chitin

molecule, Glucosamine and acetic acid were not detected in the cultures, possibly

because of their ready availability as supplementary nutrients.

CHAPTER II

METHODOLOGY

This section includes the details how the study was conducted. It includes the plans for each

stage, the actual experimentation with corresponding tools and equipments the researchers used

in performing the experiment and special procedures or techniques they have used to produce a

desired output. Materials used with corresponding measurements and equipments are listed

below:

Materials Used (for extracting chitin) :

60 g of Shrimp Shells (from 2 kilos of shrimps)

20 mL Muriatic Acid

30 mL of Lye

20 mL of Bleach

Equipments:

Stove

Casserole

Strainer

Materials Used (for experimental

setups)

4 Pots

4 potatos

12 kg of Loam soil

100 g of eggshells

Equipments:

Hammer

Rake

Procedures:

In the extraction of chitin, 2 kilos of shrimps were cooked. The shells were peeled off, gathering

a total 60 g of shrimp shells. The shells were soaked in a dilute solution of lye in water at a

boiling temperature for 15 minutes for deproteinezation. Then, the shells were soaked in muriatic

acid and water for demineralization. After 1 day, the shells were then transferred into another

bottle with dilute solution of bleach to decolorize the shells.

For the experimental setups, 4 pots were prepared, and 3 kilos of soil was put in each pot. Each

pot is mixed with 25 g of crushed egg shells. After a week, the researchers set up 4 treatments. In

pot A, 15 g of chitin were mixed with the soil. In pot B, 20 g of chitin were mixed with the soil.

In pot C, 25 g of chitin were mixed. And in pot D, no chitin were added. This is considered ad

the control setup.

CHAPTER III

RESULTS AND DISCUSSIONS

Graphical Interpretation of Data

This table shows the symptoms of Streptomyces Scaies found in the plant. S. scabies causes

variable symptoms on the surface of potato tubers including erumpent, russet, and pitted

lesions.  Erumpent lesions are raised lesions, russet lesions are defined as superficial corky tissue

that covers large areas of the tuber surface and pitted lesions are dark colored sunken areas up to

½ in deep.  Scab lesions can occur anywhere on the tuber surface and more than one type of

lesion may be present on a single tuber.  Scab affects young tubers with the lesions expanding as

the tuber matures.

Graph 1

The researchers categorized the experiment into four set-ups. Set-up A has 15 g of chitin, Setup

B has 20 g of chitin and Setup C has 25 g of chitin. The last setup is the independent setup,

which contains no amount of chitin. From the graph above, Set up C got the least lesions and the

most favorable appearance. While Setup A, B and D has the most lesions that makes its

appearance not considerable.

Graph 2

In the graph above the height of the plant in centimeters is shown. It shows that Setup C

has the highest rate of growth followed by Setup B and A. It can be inferred that the plant in

Setup C, which has the highest amount of chitin grow fastest.

Graph 3

In the graph above, the number of leaves in each setup is shown. Again, Setup C got the

most number of leaves compared to Setups A, B and D.

CHAPTER IV

SUMMARY OF FINDINGS, CONCLUSION AND RECOMMENDATION

Summary of Findings

This study was conducted to see if chitin from shrimp shells can reduce Streptomyces

Scabies in potato plants. Moreover, the study was conducted with the aim of finding a new way

to recycle shrimp shells and use it as soil conditioner. The study started in extracting chitin from

shrimp shells, undergoing three processes, demineralization, decolorization and the extraction.

After getting the chitin, four setups of potato plants were prepared with each pot having 25 g of

egg shells. After some months, the researchers gathered the results from the grown potato plant.

Set-up C gives the most favorable results because it shows the least lesions among the four

potatoes observed. It also contains the right amount of chitin in the soil and set-up C is found to

be the tallest plant that has grown.

Conclusions

Based on the researchers’ results and analysis of data, the following conclusions were

formulated.

1. It is possible to extract chitin from shrimp shells.

2. It is possible to use chitin from shrimp shells as a soil conditioner.

3. The use of shrimp shells as soil conditioner prevent the potatoes from Streptomyces

scabies.

Recommendations

From the investigations, the researchers would like to recommend a more

systematized and accurate way of extracting chitin from shrimp shells and planting

potatoes. They also recommend better and more effective techniques in growing potato

plants. More time is needed for the researchers to observe the maximum growth of the

plant because the bacteria, Streptomyces Scabies requires more time to develop.

The researchers must be patient and observant in these investigations. This is to

ensure the validity and reliability of the information gathered from the experiments.

Documentation

Materials

Boiling of Chitin

Addition of NaOH

Addition of HCl

Gathering of Chitin