ACHIEVEMENT OF ZERO EMISSIONS BY THE BIOCONVERSION OF FISHERY WASTES INTO FERTILIZER - Fertilizers: Components, Uses in Agriculture and Environmental Impacts - page 71

changed the paradigm for the waste policy, emphasizing resource recycling with zero
emissions (Mathews, 2012). Therefore, this policy urges ecologically acceptable methods for
the reutilization of fishery wastes. Recently, the conversion of fish waste into liquid fertilizer
has been demonstrated using proteolytic bacteria, indicating that the fermented broth of fish
waste could be a valuable resource for agriculture (Dao & Kim, 2011; Kim & Lee, 2009; Kim
et al., 2010). This eco-friendly means is considered the most suitable for the ideal resource
recycling of seaweed wastes with no additional emissions of waste. Therefore, this chapter
presents the results of a study that aimed to develop biodegradation products from three
different types of seaweeds (green, red and brown seaweeds) and to determine their suitability
as fertilizers. For this purpose, phytotoxicity tests, analyses of amino acid and mineral
element compositions, and hydroponic cultures were accomplished to examine the fertilizing
values of the biodegraded culture broths as fertilizers, and their fertilizing values were
compared with those values of biodegraded culture broths of fish wastes.
E XPERIMENTAL AND M ETHODS
Microorganism
Green Seaweed
The bacterial strain that was used for the biodegradation of green seaweed
polysaccharides was Bacillus licheniformis TK3-Y (GenBank Accession No.: AB374901.1),
which was isolated from silt and sandbar locations in a coastal area near Busan (Korea),
where green seaweed often drifts and accumulates. This strain formed a transparent ring on
carboxymethylcellulose (CMC) and skim milk agar around each colony according to the plate
assay (Kasana et al., 2008). Additionally, its colony had a tinge of blue on the spirit blue agar,
indicating that this strain possesses high CMCase, protease and lipase activities. Based on
microscopic observations, B. licheniformis TK3-Y was motile in its vegetative state. This
strain possessed gram-positive rods, which measured 0.5-1 μm in width and 2-4 μm in length,
and formed endospores. Because B. licheniformis TK3-Y is a novel strain that exhibits the
distinct ability to degrade CMCs, proteins and lipids, we have applied for a Korean patent
(No.: 10-2012-0040487) after depositing this strain into the Korean Agricultural Culture
Collection (KACC) as KACC91709P. The pure culture was maintained on a 1.5% nutrient
agar plate at 4 °C until use and transferred to a fresh agar plate every month. Periodically, the
potential degrading ability of this strain was checked on CMC, skim milk and spirit blue agar
by the plate assay.
Red Seaweed
The bacterial strain that was used for the biodegradation of red seaweed polysaccharides
was Bacillus alcalophilus (GenBank Accession No.: EU231621.1), which was isolated from
silt and sandbar locations in a coastal area near Busan (Korea), where red seaweed often drifts
and accumulates. This strain formed a yellow-colored ring on agar and carrageenan agar
around each colony according to the plate assay (Saraswathi et al., 2011), indicating that this
strain possesses high agarase and carrageenanase activities. Based on microscopic
observations, B. alcalophilus was motile in the vegetative state. This strain possessed gram-