Are Seafood By-Products a Potential Fertilizer?
With a dramatically increasing world population and a world catch of fish of more than 140 million tons per year, there is obviously an increased need to utilize our marine sources with more intelligence and foresight. Large amounts of protein-rich by-products from the seafood industry along with under-utilized fish are discarded or processed into fish meal and fertilizer. Novel processing methods are needed to convert seafood by-products into more profitable and marketable products. Proteins from fish processing by-products can be modified to improve their quality, functional characteristics and nutritional value by enzymatic and chemical hydrolysis. Protein from fish by-products and under-utilized species, are rich in amino acids and could be used as fertilizer.
What did we do?
In current study, fish amino acid fertilizer (FAAF) (Amino-Hirkan) was produced from Anchovy sprat, an under-utilized pelagic fish in the Caspian Sea using a commercial protease (Alcalase) at a commercial scale. In order to produce FAAF, whole anchovy fish samples were first minced using an industrial mixer, and mixed with water (1:2 w/v). With Alcalase added to the samples in a ratio of 1%, the enzymatic hydrolysis was conducted for 5 h at 50 °C. The samples were then heated at 90 °C for 10 min to inactivate the enzyme. After filtration and removing the solid particles, the liquid was used as the fertilizer. A comparison of the FAAF with four commercial fertilizers on Roshan wheat cultivar growth, chlorophyll levels, and resistance to the salt stress were measured.
What have we learned?
The FAAF induced better growth compared to the commercial fertilizers (P < 0.05). Higher total chlorophyll was observed in wheat seedling in FAAF group (P < 0.05). Total chlorophyll was 4.48 mg g-1 wet weight for the FAAF compared to 3.86-4.11 mg g-1 wet weight for the commercial fertilizers. To study the influence of the FAAF on the salt tolerance in wheat, two enzymes whose activity increases in response to stress, catalase and peroxidase levels were tested at two salinity levels (40 and 80 mM). Catalase was not affected by salinity stress (P > 0.05), but peroxidase increased with increasing salt exposure from 8.84 (control) to 11.23 at 40 mM, and to 13.54 unit mg protein-1 at 80 mM salinity in FAAF group. The peroxidase level was higher in the FAAF compared to commercial fertilizers which were 8.9-9.13 unit mg protein-1 at 40 mM and 9.05-10.22 unit mg protein-1 at 80 mM salinity.
This study indicates that fish based fertilizers can have beneficial impact for wheat and potentially other crops resulting in an increase in yield and improved stress response. FAAF can be produced to organic standards, and in a sustainable manner, providing additional market advantages.
Examples of practical fish hydrolysate plants that have been built in various locations in Alaska and worldwide for the production of fertilizers and feed ingredients are included in the presentation.
Future Plans
We are optimizing the procedure of fertilizer production from fish wastes and under-utilized fish species to increase the yield of production by applying different enzymes, temperatures, separation methods, and from different sources.
Also, different plants will be subjected to the FAAF to study the influence of the FAAF on them. ((Not sure what this means, please revise))
Authors
Mahmoudreza Ovissipour, Ph.D. School of Food Science, Washington State University mrovissi@yahoo.com
Gleyn E. Bledsoe, Ph.D. University of Idaho; Barbara Rasco, Ph.D. JD, School of Food Science, Washington State University
Additional information
We have not published the results yet.
The authors are solely responsible for the content of these proceedings. The technical information does not necessarily reflect the official position of the sponsoring agencies or institutions represented by planning committee members, and inclusion and distribution herein does not constitute an endorsement of views expressed by the same. Printed materials included herein are not refereed publications. Citations should appear as follows. EXAMPLE: Authors. 2015. Title of presentation. Waste to Worth: Spreading Science and Solutions. Seattle, WA. March 31-April 3, 2015. URL of this page. Accessed on: today’s date.