Methods in Molecular Biology (2020) 1980: 95–101
DOI 10.1007/7651_2018_129
© Springer Science+Business Media New York 2018
Published online: 27 March 2018
Determining Dissolved and Biogenic Silica
Jaana Koistinen, Mervi Sjo ¨ blom, and Kristian Spilling
Abstract
Most algae do not use silicon in any form with one notable exception, diatoms. Silicon is a major
constituent of diatoms. Diatoms are characterized by high growth rates and are often one of the key groups
in forming algal blooms in natural waters, and as such it is an interesting group for cultivation. In this
chapter we present methods for determining dissolved silica (DSi) and biogenic silica (BSi), oxide forms of
silicon, based on colorimetric methods. BSi is determined after filtration and alkaline digestion.
Keywords Biogenic silica, Diatoms, Dissolved silica, Silicon
1 Introduction
Most algae do not use silicon (Si) in any form with one notable
exception, diatoms, in addition to some smaller groups such as
silicoflagellates. Silicon, one of the most abundant elements on
the surface of the earth, is a major constituent of diatoms and
may become limiting for diatom growth. Silicon appears as the
oxide (silica) or silicates, most of the silicon being bound to rocks
as silicate minerals. Chemical weathering brings dissolved silica
(DSi), the form that it is available for diatoms. Diatoms are characterized by high growth rates and are often one of the key groups
in forming algal blooms in natural waters, and as such it is an
interesting group for cultivation [1, 2]. Part of the success of the
diatoms has been attributed to the fact that they have silicified cell
walls, hydrated amorphous silica forming the outer cell wall,
termed frustules (Fig. 1). The metabolic cost of producing silicified
walls has been hypothesized to the lower than for building carbon
based (e.g., cellulose) walls and provide the diatoms with the
potentially very high (>1/d) maximum growth rate [3, 4].
The diatom frustules consist of two halves that are joined in the
middle similar to a box with a lid, where both the box and lid part
are of equal size in most species. During cell division, both of the
two halves become the lid part of the new cell. The old lid forms a
95
DOI 10.1007/7651_2018_129
© Springer Science+Business Media New York 2018
Published online: 27 March 2018
Determining Dissolved and Biogenic Silica
Jaana Koistinen, Mervi Sjo ¨ blom, and Kristian Spilling
Abstract
Most algae do not use silicon in any form with one notable exception, diatoms. Silicon is a major
constituent of diatoms. Diatoms are characterized by high growth rates and are often one of the key groups
in forming algal blooms in natural waters, and as such it is an interesting group for cultivation. In this
chapter we present methods for determining dissolved silica (DSi) and biogenic silica (BSi), oxide forms of
silicon, based on colorimetric methods. BSi is determined after filtration and alkaline digestion.
Keywords Biogenic silica, Diatoms, Dissolved silica, Silicon
1 Introduction
Most algae do not use silicon (Si) in any form with one notable
exception, diatoms, in addition to some smaller groups such as
silicoflagellates. Silicon, one of the most abundant elements on
the surface of the earth, is a major constituent of diatoms and
may become limiting for diatom growth. Silicon appears as the
oxide (silica) or silicates, most of the silicon being bound to rocks
as silicate minerals. Chemical weathering brings dissolved silica
(DSi), the form that it is available for diatoms. Diatoms are characterized by high growth rates and are often one of the key groups
in forming algal blooms in natural waters, and as such it is an
interesting group for cultivation [1, 2]. Part of the success of the
diatoms has been attributed to the fact that they have silicified cell
walls, hydrated amorphous silica forming the outer cell wall,
termed frustules (Fig. 1). The metabolic cost of producing silicified
walls has been hypothesized to the lower than for building carbon
based (e.g., cellulose) walls and provide the diatoms with the
potentially very high (>1/d) maximum growth rate [3, 4].
The diatom frustules consist of two halves that are joined in the
middle similar to a box with a lid, where both the box and lid part
are of equal size in most species. During cell division, both of the
two halves become the lid part of the new cell. The old lid forms a
95