Team:ULaval/Syrup Microbiology
Project
Human Practices
Team
Collaboration & Communication
Collaboration & Communication
Going above and beyond - Microbiology
Choosing what we wanted to do
Throughout our journey in the world of ropy maple syrup, we quickly learned that this is an under researched subject. This is because, for now, ropy maple syrup isn’t considered fit for consumption and thus no efforts were put into characterizing and understanding it.
The reason it is not considered fit for consumption is based on the correlation with fermented maple syrup which can contain toxins since ropy maple syrup is created by fermentative bacteria. This information was given to us during meetings with the PPAQ (see our Integrated Human Practices page for more info). Although there isn’t any direct proof of toxins in ropy syrup, research was halted because of the belief that a product with toxins is not worth researching. Given that our team has limited knowledge on toxins and their production, we wanted to use one of our strengths to address this potential problem : microbiology.
Our main project, aSAP, consists of an enzymatic treatment to reduce the viscosity of ropy syrup. However, our team wanted to go beyond our main goal for the project. This is why we decided to explore outside the field of synthetic biology, dipping into microbiology to further advance knowledge on ropy maple syrup.
A way that our team could further help the maple industry is by characterizing the microbiological content of ropy maple syrup. We wanted to confirm the presence or find new microorganisms responsible for the viscosity of ropy maple syrup. Next, we wanted to research the ecology of each microorganism we find. This way, we can help producers understand the origin of the microorganisms responsible for ropy maple syrup and what they can change to prevent this problem.
We hope that, down the line, this research could help experts identify toxin producing microorganisms, which is an important factor in the implementation of our project in the real world. Finally, we expect to help governmental and private entities make clearer decisions on their regulations and propose an alternative solution for ropy syrup (see Project Implementation page for more info).
To date, there are only two recent and detailed studies that identify the microbiological content of maple syrup : one in normal maple syrup (Filteau et al., 2011) and one in ropy maple syrup (Lagacé et al., 2018). Thus, our team wanted to help gain more insight on this under researched subject and help characterise the microbiological content of ropy maple syrup.
Our Research
We believed that we would find a species of Leuconostoc as the culprit responsible for the ropiness of the syrup. Regarding toxins, we aren’t quite sure that there are any, given the lack of evidence and the fact that most microorganisms related to ropy maple syrup production can also be found in normal maple syrup. Unfortunately, we believe that the microorganisms that we will find will be quite under researched, meaning that we won’t be able to directly determine if toxicity is present. This is why toxin identification is not the main objective of our side project.
For more information about the methods, go to our Experiments page.
Here are a few preliminary results to our findings:
Table 1 gives you an overview of which microorganisms we found in all three ropy syrup samples we had access to. Out of the eight microorganisms detected, five of them are from the Leuconostoc genus.
Table 1 : Organisms found in ropy maple syrup by a BLAST search with the DNA sequences and its percentage of identity (% ID). Follows a brief summary of the source of each microorganism.
As previously reported (Lagacé et al., 2018), ropy maple syrup is contaminated with Leuconostoc mesentoroides, an organism partially responsible for the known texture of ropy maple syrup. Another culprit of this texture could be Leuconostoc pseudomesentoroides (Table 1), as it has been described to produce dextrans as well (Zhou et al., 2018). All of the other organisms we found do not produce dextrans. To our knowledge, we are the first to identify this microorganism in ropy maple syrup or normal maple syrup.
We also identified two other microorganisms that weren’t previously detected in ropy syrup or maple syrup : Sphingomonas paucimobilis and Citeromyces matriensis (Table 1). S. paucimobilis is a bacteria frequently isolated in water, soil and other sources in the natural environment (Ryan et al.). We believe that this bacteria finds its way into ropy syrup through contamination in the tubing system, which is found in the forest.
C. matritensis, on the other hand, is a yeast frequently isolated in food products with high osmolarity, such as food in syrup, sugar or condensed milk (Kurtzman et al., 2011). We don’t know if this yeast finds its way in food through human contamination or not. Although, it is not surprising to find this yeast in an environment such as maple syrup because of its high osmolarity.
Rhodoturula glutinis was already identified by Marie Filteau (Filteau, 2011). This organism is commonly found in various environments, such as soil, air, deep water, plastic, or even toothbrushes (Wirth et al., 2012). Given that it is an organism found in many environments, we can't assert that the presence of this microorganisme is not due to human contamination, but knowing it is widely present in nature we are confident that it might be from natural sources. Nevertheless, this organism isn’t responsible for ropy syrup’s unique characteristics because it is found in normal maple syrup as well (Filteau, 2011).
Like any study, ours has its limits. When trying to identify microorganisms in an environment, the biggest limit is that only cultivable organisms can be easily detected. In fact, it is estimated that less than 2 % of bacteria can’t be cultivable and thus can’t be identified (Wade, 2002). This means that it is virtually impossible, with the technology currently available, to identify all microorganisms present in a specific environment.
Another limit to our study is that we only characterised viable microorganisms present in the final product of ropy maple syrup, which has already been boiled for a long time. This step kills most microorganisms found in the maple sap meaning that we aren’t able to detect most organisms present in maple sap and in the biofilms found in the tubing system. The high osmolarity of maple syrup also reduces the diversity of microorganisms that can be revealed from our analysis. Those two factors are the reasons why maple syrup can be shelved for a long period of time. This might also mean that we have identified microorganisms present in the final product but not in the sap, such as C. matritensis which is only found in high osmolarity environments.
In sum, in this side project, we are the first to identify three microorganisms in ropy maple syrup : L. pseudomesentoroides, S. paucimobilis and C. matriensis. Most of which do not originate from human contamination, further explaining why it is difficult to predict and prevent microbiological contamination that generates ropy maple syrup.
A Gap in Knowledge
Throughout our journey in the world of ropy maple syrup, we quickly learned that this is an under researched subject. This is because, for now, ropy maple syrup isn’t considered fit for consumption and thus no efforts were put into characterizing and understanding it.
The reason it is not considered fit for consumption is based on the correlation with fermented maple syrup which can contain toxins since ropy maple syrup is created by fermentative bacteria. This information was given to us during meetings with the PPAQ (see our Integrated Human Practices page for more info). Although there isn’t any direct proof of toxins in ropy syrup, research was halted because of the belief that a product with toxins is not worth researching. Given that our team has limited knowledge on toxins and their production, we wanted to use one of our strengths to address this potential problem : microbiology.
Helping Fill the Gap
Our main project, aSAP, consists of an enzymatic treatment to reduce the viscosity of ropy syrup. However, our team wanted to go beyond our main goal for the project. This is why we decided to explore outside the field of synthetic biology, dipping into microbiology to further advance knowledge on ropy maple syrup.
A way that our team could further help the maple industry is by characterizing the microbiological content of ropy maple syrup. We wanted to confirm the presence or find new microorganisms responsible for the viscosity of ropy maple syrup. Next, we wanted to research the ecology of each microorganism we find. This way, we can help producers understand the origin of the microorganisms responsible for ropy maple syrup and what they can change to prevent this problem.
We hope that, down the line, this research could help experts identify toxin producing microorganisms, which is an important factor in the implementation of our project in the real world. Finally, we expect to help governmental and private entities make clearer decisions on their regulations and propose an alternative solution for ropy syrup (see Project Implementation page for more info).
To date, there are only two recent and detailed studies that identify the microbiological content of maple syrup : one in normal maple syrup (Filteau et al., 2011) and one in ropy maple syrup (Lagacé et al., 2018). Thus, our team wanted to help gain more insight on this under researched subject and help characterise the microbiological content of ropy maple syrup.
Our Research
Hypothesis
We believed that we would find a species of Leuconostoc as the culprit responsible for the ropiness of the syrup. Regarding toxins, we aren’t quite sure that there are any, given the lack of evidence and the fact that most microorganisms related to ropy maple syrup production can also be found in normal maple syrup. Unfortunately, we believe that the microorganisms that we will find will be quite under researched, meaning that we won’t be able to directly determine if toxicity is present. This is why toxin identification is not the main objective of our side project.
Method
For more information about the methods, go to our Experiments page.
Here are a few preliminary results to our findings:
Figure 1: Image of the Petri dishes with the microorganisms found in
all three samples of ropy maple syrup, cultured on LB or 2YT medium.
Figure 2: Agarose gel of our 16S and 18S PCR
amplification of the microorganisms isolated in Figure 1.
Findings
Table 1 gives you an overview of which microorganisms we found in all three ropy syrup samples we had access to. Out of the eight microorganisms detected, five of them are from the Leuconostoc genus.
Table 1 : Organisms found in ropy maple syrup by a BLAST search with the DNA sequences and its percentage of identity (% ID). Follows a brief summary of the source of each microorganism.
Organism
% ID
Source
Sequence
Leuconostoc mesenteroides subsp. Dextranicum (bacteria)
100
Mainly found on green plants, on their leaves or grains for example (Limsowtin
et al., 2002). Also found in milk products (McAuliffe, 2017)
AATAAAACTTAGTGTCGCATGACACAAAGTTAAAAGGCGCTTCGGCGTCACCTAGAGATGGATCCGCGGTGCATTAGTTAGTTGGTGGGGTAAAGGCCTACCAAGACAATGATGCATAGCCGAGTTGAGAGACTGATCGGCCACATTGGGACTGAGACACGGCCCAAACTCCTACGGGAGGCTGCAGTAGGGAATCTTCCACAATGGGCGAAAGCCTGATGGAGCAACGCCGCGTGTGTGATGAAGGCTTTCGGGTCGTAAAGCACTGTTGTATGGGAAGAACAGCTAGAATAGGAAATGATTTTAGTTTGACGGTACCATACCAGAAAGGGACGGCTAAATACGTGCCAGCAGCCGCGGTAATACGTATGTCCCGAGCGTTATCCGGATTTATTGGGCGTAAAGCGAGCGCAGACGGTTTATTAAGTCTGATGTGAAAGCCCGGAGCTCAACTCCGGAATGGCATTGGAAACTGGTTAACTTGAGTGCAGTAGAGGTAAGTGGAACTCCATGTGTAGCGGTGGAATGCGTAGATATATGGAAGAACACCAGTGGCGAAGGCGGCTTACTGGACTGCAACTGACGTTGAGGCTCGAAAGTGTGGGTAGCAAACAGGATTAGATACCCTGGTAGTCCACACCGTAAACGATGAACACTAGGTGTTAGGAGGTTTCCGCCTCTTAGTGCCGAAGCTAACGCATTAAGTGTTCCGCCTGGGGAGTACGACCGCAAGGTTGAAACTCAAAGGAATTGACGGGGACCCGCACAAGCGGTGGAGCATGTGGTTTAATTCGAAGCAACGCGAAGAACCTTACCAGGTCTTGACATCCTTTGAAGCTTTTAGAGATAGAAGTGTTCTCTTCGGAGACAAAGTGACAGGTGGTGCATGGTCGTCGTCAGCTCGTGTCGTGAGATGTTGGGTTAAGTCCCGCAACGAGCGCAACCCTTATTGTTAGTTGCCAGCATTCAGATGGGCACTCTAGCGAGACTGCCGGTGACAAACCGGAGGAAGGCGGGGACGACGTCAGATCATCATGCCCCTTATGACCTGGGCTACACACGTGCTACAATGGCGTATACAACGAGTTGCCAACCCGCG
Sphingomonas paucimobilis (bacteria)
99.23
Isolated from water, soil and other sources in the natural environment (Ryan et
al.)
GCCCTTAGGTTCGGAATAACAGCTGGAACACAGGCTGCTAATACCGGATGATATCGCGAGATCAAAGATTTATCGCCTGAGGATGAGCCCGCGTTGGATTAGGTAGTTGGTGGGGTAAAGGCCTACCAAGCCGACGATCCATAGCTGGTCTGAGAGGATGATCAGCCACACTGGGACTGAGACACGGCCCAGACTCCTACGGGAGGCAGCAGTGGGGAATATTGGACAATGGGCGAAAGCCTGATCCAGCAATGCCGCGTGAGTGATGAAGGCCCTAGGGTTGTAAAGCTCTTTTACCCGGGAAGATAATGACTGTACCGGGAGAATAAGCCCCGGCTAACTCCGTGCCAGCAGCCGCGGTAATACGGAGGGGGCTAGCGTTGTTCGGAATTACTGGGCGTAAAGCGCACGTAGGCGGCTTTGTAAGTCAGAGGTGAAAGCCTGGAGCTCAACTCCAGAACTGCCTTTGAGACTGCATCGCTTGAATCCAGGAGAGGTCAGTGGAATTCCGAGTGTAGAGGTGAAATTCGTAGATATTCGGAAGAACACCAGTGGCGAAGGCGGCTGACTGGACTGGTATTGACGCTGAGGTGCGAAAGCGTGGGGAGCAAACAGGATTAGATACCCTGGTAGTCCACGCCGTAAACGATGATAACTAGCTGTCCGGGCACTTGGTGCTTGGGTGGCGCAGCTAACGCATTAAGTTATCCGCCTGGGGAGTACGGCCGCAAGGTTAAAACTCAAAGGAATTGACGGGGGCCTGCACAAGCGGTGGAGCATGTGGTTTAATTCGAAGCAACGCGCAGAACCTTACCAGCGTTTGACATGGTAGGACGACTTCCAGAGATGGATTTCTTCCCTTCGGGGACCTACACACAGGTGCTGCATGGCTGTCGTCAGCTCGTGTCGTGAGATGTTGGGTTAAGTCCCGCAACGAGCGCAACCCTCGCCTTTAGTTACCATCATTTGGTTGGGTACTCTAAAGGAACCGCCGGTGATAAGCCGGAGGAAGGTGGGGATGACGTCAAGTCCTCATGGCCCTTACGCGCTGGGCTNYNCACGTGNTACAATGGCAACTACAGTGGGCAGCGACCCTGCGAGGGCGAGCTAATCCCCAAAAGTTGTCTCANNNCGGATTGTTCTCTGCAACTCGAGAGCATGAAGGCGG
Leuconostoc mesenteroides subsp. dextranicum strain (bacteria)
99.91
Mainly found on green plants, on their leaves or grains for example. (Limsowtin
et al., 2002). Also found in milk products (McAuliffe, 2017)
GAATAAAACTTAGTGTCGCATGACACAAAGTTAAAAGGCGCTTCGGCGTCACCTAGAGATGGATCCGCGGTGCATTAGTTAGTTGGTGGGGTAAAGGCCTACCAAGACAATGATGCATAGCCGAGTTGAGAGACTGATCGGCCACATTGGGACTGAGACACGGCCCAAACTCCTACGGGAGGCTGCAGTAGGGAATCTTCCACAATGGGCGAAAGCCTGATGGAGCAACGCCGCGTGTGTGATGAAGGCTTTCGGGTCGTAAAGCACTGTTGTATGGGAAGAACAGCTAGAATAGGAAATGATTTTAGTTTGACGGTACCATACCAGAAAGGGACGGCTAAATACGTGCCAGCAGCCGCGGTAATACGTATGTCCCGAGCGTTATCCGGATTTATTGGGCGTAAAGCGAGCGCAGACGGTTTATTAAGTCTGATGTGAAAGCCCGGAGCTCAACTCCGGAATGGCATTGGAAACTGGTTAACTTGAGTGCAGTAGAGGTAAGTGGAACTCCATGTGTAGCGGTGGAATGCGTAGATATATGGAAGAACACCAGTGGCGAAGGCGGCTTACTGGACTGCAACTGACGTTGAGGCTCGAAAGTGTGGGTAGCAAACAGGATTAGATACCCTGGTAGTCCACACCGTAAACGATGAACACTAGGTGTTAGGAGGTTTCCGCCTCTTAGTGCCGAAGCTAACGCATTAAGTGTTCCGCCTGGGGAGTACGACCGCAAGGTTGAAACTCAAAGGAATTGACGGGGACCCGCACAAGCGGTGGAGCATGTGGTTTAATTCGAAGCAACGCGAAGAACCTTACCAGGTCTTGACATCCTTTGAAGCTTTTAGAGATAGAANTGTTCTCTTCGGAGACAAAGTGACAGGTGGTGCATGGTCGTCGTCAGCTCGTGTCGTGAGATGTTGGGTTAAGTCCCGCAACGAGCGCAACCCTTATTGTTAGTTGCCAGCATTCAGATGGGCACTCTAGCGAGACTGCCGGTGACAAACCGGAGGAAGGCGGGGACGACGTCAGATCATCATGCCCCTTATGACCTGGGCTACACACGTGCTACAATGGCGTATACAACGAGTTGCCAACCCGCG
Citeromyces matritensis (yeast)
100
Isolated in food products with high osmolarity, such as food in syrup, sugar or
condensed milk. It should be considered as a food spoilage organism (Kurtzman et
al., 2011)
GCATGTCTAAGTATAAGCAATTTATACAGTGAAACTGCGAATGGCTCATTAAATCAGTTATCGTTTATTTGATAGTACCTTTACTACATGGTTATAACCGTGGTAATTCTAGAGCTAATACATGCTAAAAATCCCGACTGTTTGGAAGGGATGTATTTATTAGATAAAAAACCAATGCTCTTCGGAGCTCTTGGATGATTCATAATAACTTTTCGAATCGCATGGCTTCATTGCCGGCGATGGTTCATTCAAATTTCTGCCCTATCAACTTTCGATGGTAGGATAGTGGCCTACCATGGTTTCAACGGGTAACGGGGAATTAGGGTTCGATTCCGGAGAGGGAGCCTGAGAAACGGCTACCACATCCAAGGAAGGCAGCAGGCGCGCAAATTACCCAATCCTGACACAGGGAGGTAGTGACAATACATAACGATACAGGGCCCTTTCGGGTCTTGTAATTGGAATGAGTACAATGTAAATACCTTAACGAGGAACAATTGGAGGGCAAGTCTGGTGCCAGCAGCCGCGGTAATTCCAGCTCCAATAGCGTATATTAAAGTTGTTGCAGTTAAAAAGCTCGTAGTTGAACCTTGGGCTTGGTTGGCCGGTCCGCTTTTTGGCGAGTACTGGATCCAACCGAGCCTTTCCTTCTGGCTAACCTTCTGCCCTTTACGGGGTGGTTGGCGAACCAGGACTTTTACCTTGAGAAAATTAGAGTGTTCAAAGCAGGCGTATAGCTCGAATATGTTAGCATGGAATAATAGAATAGGACGTTATGGTTCTATTTTGTTGGTTTCTAGGACCATCGTAATGATTAATAGGGACGGTCGGGGGCATCAGTATTCAGTTGTCAGAGGTGAAATTCTTGGATTTACTGAAGACTAACTACTGCGAAAGCATTTGCCAAGGACGTTTTCATTAATCAAGAACGAAAGTTAGGGGATCGAAGATGATCAGATACCGTCGTAGTCTTAACCATAAACTATGCCGACTAGGGATCGGGTGTTGTTCTTTTATTGACTCACTCGGCACCTTACGAGAAATCAAAGTCTTTGGGTTCTGGGGGGAGTATGGTCGCAAGGCTGAAACTTAAAGGAATTGACGGAAGGGCACCACCAGGAGTGGAGCCTGCGGCTTAATTTGACTCAACACGGGGAAACTCACCAGGTCCAGACACAATAAGGATTGACAGATTGAGAGCTCTTTCTTGATTTTGTGGGTGGTGGTGCATGGCCGTTCTTAGTTGGTGGAGTGATTTGTCTGCTTAATTGCGATAACGAACGAGACCTTAACCTACTAAATAGTGCTACTAGCTTTTGCTGGTTTTGCACTTCTTAGAGGGACTATCTATTTCAAGTAGATGGAAGTTTGAGGCAATAACAGGTCTGTGATGCCCTTAGACGTTCTGGGCCGCACGCGCGCTACACTGACGGAGCCAACGAGTACTAACCTTGGCCGAGAGGTCTGGGTAATCTTGTTAAACTCCGTCGTGCTGGGGATAGAGCATTGTAATTATTGCTCTTCAACGAGGAATTCCTAGTAAGCGCAAGTCATCAGCTTGCGTTGATTACGTCCCTGCCCTTTGTACACACCGCCCGTCGCTACTACCGATTGAATGGCTTAGTGAGGCTTCCGGATTGGTCCAAAGAAGGAGGCAACTCCCTCTTGGGACTGAAAAGCTAGTCAAACTTGGT
Rhodoturula glutinis (yeast)
99.94
Ubiquitous and found in many environments, even extreme ones. Found in soil,
air, plastic, deep water environments, goat milk, toothbrushes, etc. (Wirth et
al., 2012)
TGCATGTCTAAGTTTAAGCAATAAACAGTGAAACTGCGAATGGCTCATTAAATCAGTCATAGTTTATTTGATGGTACCTTACTACATGGATAACTGTGGTAATTCTAGAGCTAATACATGCTGAAAAATCCCGACTTCTGGAAGGGATGTATTTATTAGATCCAAAACCAATGGCCTTCGGGTCCCTATGGTGAATCATAATAACTGCTCGAATCGCATGGCCTTGCGCCGGCGATGCTTCATTCAAATATCTGCCCTATCAACTTTCGATGGTAGGATAGAGGCCTACCATGGTGATGACGGGTAACGGGGAATAAGGGTTCGATTCCGGAGAGAGGGCCTGAGAAACGGCCCTCAGGTCTAAGGACACGCAGCAGGCGCGCAAATTATCCCCTGGCAACACTTTGCCGAGATAGTGACAATAAATAACAATGCAGGGCTCTTACGGGTCTTGCAATTGGAATGAGTACAATTTAAATCCCTTAACGAGGATCAATTGGAGGGCAAGTCTGGTGCCAGCAGCCGCGGTAATTCCAGCTCCAATAGCGTATATTAAAATTGTTGCCGTTAAAAAGCTCGTAGTCGAACTTCGGGCTCTGTCAGCCGGTCCGCCTTCTTGGTGTGTACTTGTTTGATGGAGCCTTACCTCCTGGTGAACGGCGATGTCCTTTACTGGGTGTCGTCGCAAACCAGGACTTTTACTTTGAAAAAATTAGAGTGTTCAAAGCAGGCCTTTGCCCGAATACATTAGCATGGAATAATAAAATAGGACGCGCGTTCCCATTTTGTTGGCTTTCTGAGATCGCCGTAATGATTAATAGGGATAGTTGGGGGCATTTGTATTCCGTCGTCAGAGGTGAAATTCTTGGATTGCCGGAAGACAAACTACTGCGAAAGCATTTGCCAAGGATGTTTTCATTGATCAAGAACGAAGGAAGGGGGATCGAAAACGATTAGATACCGTTGTAGTCTCTTCTGTAAACTATGCCAATTGGGGATCGGTACAGGATTTTTAATGACTGTATCGGCACCCGAAGAGAAATCTTTAAATGAGGTTCGGGGGGGAGTATGGTCGCAAGGCTGAAACTTAAAGGAATTGACGGAAGGGCACCACCAGGTGTGGAGCCTGCGGCTTAATTTGACTCAACACGGGGAAACTCACCAGGTCCAGACACAATAAGGATTGACAGATTGATAGCTCTTTCTTGATCTTGTGGTTGGTGGTGCATGGCCGTTCTTAGTTGGTGGAGTGATTTGTCTGGTTAATTCCGATAACGAACGAGACCTTAACCTGCTAAATAGACCAGCCGGCTTTGGCTAGCTGCTGTCTTCTTAGAGGGACTATCAGCGTTTAGCTGATGGAAGTTTGAGGCAATAACAGGTCTGTGATGCCCTTAGATGTTCTGGGCCGCACGCGCGCTACACTGACAGAGCCAGCGAGTCTACCACCTTTGCCGGAAGGCATGGGTAATCTTGTGAAACTCTGTCGTGATGGGGATAGAACATTGCAATTATTGTTCTTCAACGAGGAATACCTAGTAAGCGTGATTCATCAGATCGCGTTGATTACGTCCCTGCCCTTTGTACACACCGCCCGTCGCTACTACCGATTGAATGGCTTAGTGAGGCCTCCGGATTGGCTATTGGGAGCTCGCGAGAGCACCCGACTGCCGAGAAGTTGTACGAACTTGGTC
Leuconostoc pseudomesenteroides (bacteria)
100
Mainly found on green plants, on their leaves or grains for example. (Limsowtin
et al., 2002). Also found in milk products (McAuliffe, 2017)
AATAAAACTCAGTGTCGCATGACACAAAGTTAAAAGGCGCTTTGGCGTCACCTAGAGATGGATCCGCGGTGCATTAGTTAGTTGGTGGGGTAAAGGCCTACCAAGACAATGATGCATAGCCGAGTTGAGAGACTGATCGGCCACATTGGGACTGAGACACGGCCCAAACTCCTACGGGAGGCTGCAGTAGGGAATCTTCCACAATGGGCGAAAGCCTGATGGAGCAACGCCGCGTGTGTGATGAAGGCTTTCGGGTCGTAAAGCACTGTTGTATGGGAAGAACAGCTAGAATAGGGAATGATTTTAGTTTGACGGTACCATACCAGAAAGGGACGGCTAAATACGTGCCAGCAGCCGCGGTAATACGTATGTCCCGAGCGTTATCCGGATTTATTGGGCGTAAAGCGAGCGCAGACGGTTGATTAAGTCTGATGTGAAAGCCCGGAGCTCAACTCCGGAATGGCATTGGAAACTGGTTAACTTGAGTGCAGTAGAGGTAAGTGGAACTCCATGTGTAGCGGTGGAATGCGTAGATATATGGAAGAACACCAGTGGCGAAGGCGGCTTACTGGACTGTAACTGACGTTGAGGCTCGAAAGTGTGGGTAGCAAACAGGATTAGATACCCTGGTAGTCCACACCGTAAACGATGAACACTAGGTGTTAGGAGGTTTCCGCCTCTTAGTGCCGAAGCTAACGCATTAAGTGTTCCGCCTGGGGAGTACGACCGCAAGGTTGAAACTCAAAGGAATTGACGGGGACCCGCACAAGCGGTGGAGCATGTGGTTTAATTCGAAGCAACGCGAAGAACCTTACCAGGTCTTGACATCCTTTGAAGCTTTTAGAGATAGAAGTGTTCTCTTCGGAGACAAAGTGACAGGTGGTGCATGGTCGTCGTCAGCTCGTGTCGTGAGATGTTGGGTTAAGTCCCGCAACGAGCGCAACCCTTATTGTTAGTTGCCAGCATTCAGATGGGCACTCTAGCGAGACTGCCGGTGACAAACCGGAGGAAGGCGGGGACGACGTCAGATCATCATGCCCCTTATGACCTGGG
Leuconostoc mesenteroides subsp. dextranicum (bacteria)
100
Mainly found on green plants, on their leaves or grains for example. (Limsowtin
et al., 2002). Also found in milk products (McAuliffe, 2017)
GAATAAAACTTAGTGTCGCATGACACAAAGTTAAAAGGCGCTTCGGCGTCACCTAGAGATGGATCCGCGGTGCATTAGTTAGTTGGTGGGGTAAAGGCCTACCAAGACAATGATGCATAGCCGAGTTGAGAGACTGATCGGCCACATTGGGACTGAGACACGGCCCAAACTCCTACGGGAGGCTGCAGTAGGGAATCTTCCACAATGGGCGAAAGCCTGATGGAGCAACGCCGCGTGTGTGATGAAGGCTTTCGGGTCGTAAAGCACTGTTGTATGGGAAGAACAGCTAGAATAGGAAATGATTTTAGTTTGACGGTACCATACCAGAAAGGGACGGCTAAATACGTGCCAGCAGCCGCGGTAATACGTATGTCCCGAGCGTTATCCGGATTTATTGGGCGTAAAGCGAGCGCAGACGGTTTATTAAGTCTGATGTGAAAGCCCGGAGCTCAACTCCGGAATGGCATTGGAAACTGGTTAACTTGAGTGCAGTAGAGGTAAGTGGAACTCCATGTGTAGCGGTGGAATGCGTAGATATATGGAAGAACACCAGTGGCGAAGGCGGCTTACTGGACTGCAACTGACGTTGAGGCTCGAAAGTGTGGGTAGCAAACAGGATTAGATACCCTGGTAGTCCACACCGTAAACGATGAACACTAGGTGTTAGGAGGTTTCCGCCTCTTAGTGCCGAAGCTAACGCATTAAGTGTTCCGCCTGGGGAGTACGACCGCAAGGTTGAAACTCAAAGGAATTGACGGGGACCCGCACAAGCGGTGGAGCATGTGGTTTAATTCGAAGCAACGCGAAGAACCTTACCAGGTCTTGACATCCTTTGAAGCTTTTAGAGATAGAAGTGTTCTCTTCGGAGACAAAGTGACAGGTGGTGCATGGTCGTCGTCAGCTCGTGTCGTGAGATGTTGGGTTAAGTCCCGCAACGAGCGCAACCCTTATTGTTAGTTGCCAGCATTCAGATGGGCACTCTAGCGAGACTGCCGGTGACAAACCGGAGGAAGGCGGGGACGACGTCAGATCATCATGCCCCTTATGACCTGGGCTACACACGTGCTACAATGGCGTATACAACGAGTTGCCAACCCGCGA
Leuconostoc pseudomesenteroides (bacteria)
99.91
Mainly found on green plants, on their leaves or grains for example. (Limsowtin
et al., 2002). Also found in milk products (McAuliffe, 2017)
AATAAAACTCAGTGTCGCATGACACAAAGTTAAAAGGCGCTTTGGCGTCACCTAGAGATGGATCCGCGGTGCATTAGTTAGTTGGTGGGGTAAAGGCCTACCAAGACAATGATGCATAGCCGAGTTGAGAGACTGATCGGCCACATTGGGACTGAGACACGGCCCAAACTCCTACGGGAGGCTGCAGTAGGGAATCTTCCACAATGGGCGAAAGCCTGATGGAGCAACGCCGCGTGTGTGATGAAGGCTTTCGGGTCGTAAAGCACTGTTGTATGGGAAGAACAGCTAGAATAGGGAATGATTTTAGTTTGACGGTACCATACCAGAAAGGGACGGCTAAATACGTGCCAGCAGCCGCGGTAATACGTATGTCCCGAGCGTTATCCGGATTTATTGGGCGTAAAGCGAGCGCAGACGGTTGATTAAGTCTGATGTGAAAGCCCGGAGCTCAACTCCGGAATGGCATTGGAAACTGGTTAACTTGAGTGCAGTAGAGGTAAGTGGAACTCCATGTGTAGCGGTGGAATGCGTAGATATATGGAAGAACACCAGTGGCGAAGGCGGCTTACTGGACTGTAACTGACGTTGAGGCTCGAAAGTGTGGGTAGCAAACAGGATTAGATACCCTGGTAGTCCACACCGTAAACGATGAACACTAGGTGTTAGGAGGTTTCCGCCTCTTAGTGCCGAAGCTAACGCATTAAGTGTTCCGCCTGGGGAGTACGACCGCAAGGTTGAAACTCAAAGGAATTGACGGGGACCCGCACAAGCGGTGGAGCATGTGGTTTAATTCGAAGCAACGCGAAGAACCTTACCAGGTCTTGACATCCTTTGAAGCTTTTAGAGATAGAAGTGTTCTCTTCGGAGACAAAGTGACAGGTGGTGCATGGTCGTCGTCAGCTCGTGTCGTGAGATGTTGGGTTAAGTCCCGCAACGAGCGCAACCCTTATTGTTAGTTGCCAGCATTCAGATGGGCACTCTAGCGAGACTGCCGGTGACAAACCGGAGGAAGGCGGGGACGACGTCAGATCATCATGCCCCTTATGACCTGGGCTATCACACGTGCTACAATGGCGTATACAACGAGTTGCCAACCCGCG
As previously reported (Lagacé et al., 2018), ropy maple syrup is contaminated with Leuconostoc mesentoroides, an organism partially responsible for the known texture of ropy maple syrup. Another culprit of this texture could be Leuconostoc pseudomesentoroides (Table 1), as it has been described to produce dextrans as well (Zhou et al., 2018). All of the other organisms we found do not produce dextrans. To our knowledge, we are the first to identify this microorganism in ropy maple syrup or normal maple syrup.
We also identified two other microorganisms that weren’t previously detected in ropy syrup or maple syrup : Sphingomonas paucimobilis and Citeromyces matriensis (Table 1). S. paucimobilis is a bacteria frequently isolated in water, soil and other sources in the natural environment (Ryan et al.). We believe that this bacteria finds its way into ropy syrup through contamination in the tubing system, which is found in the forest.
C. matritensis, on the other hand, is a yeast frequently isolated in food products with high osmolarity, such as food in syrup, sugar or condensed milk (Kurtzman et al., 2011). We don’t know if this yeast finds its way in food through human contamination or not. Although, it is not surprising to find this yeast in an environment such as maple syrup because of its high osmolarity.
Rhodoturula glutinis was already identified by Marie Filteau (Filteau, 2011). This organism is commonly found in various environments, such as soil, air, deep water, plastic, or even toothbrushes (Wirth et al., 2012). Given that it is an organism found in many environments, we can't assert that the presence of this microorganisme is not due to human contamination, but knowing it is widely present in nature we are confident that it might be from natural sources. Nevertheless, this organism isn’t responsible for ropy syrup’s unique characteristics because it is found in normal maple syrup as well (Filteau, 2011).
Limits
Like any study, ours has its limits. When trying to identify microorganisms in an environment, the biggest limit is that only cultivable organisms can be easily detected. In fact, it is estimated that less than 2 % of bacteria can’t be cultivable and thus can’t be identified (Wade, 2002). This means that it is virtually impossible, with the technology currently available, to identify all microorganisms present in a specific environment.
Another limit to our study is that we only characterised viable microorganisms present in the final product of ropy maple syrup, which has already been boiled for a long time. This step kills most microorganisms found in the maple sap meaning that we aren’t able to detect most organisms present in maple sap and in the biofilms found in the tubing system. The high osmolarity of maple syrup also reduces the diversity of microorganisms that can be revealed from our analysis. Those two factors are the reasons why maple syrup can be shelved for a long period of time. This might also mean that we have identified microorganisms present in the final product but not in the sap, such as C. matritensis which is only found in high osmolarity environments.
Conclusion
In sum, in this side project, we are the first to identify three microorganisms in ropy maple syrup : L. pseudomesentoroides, S. paucimobilis and C. matriensis. Most of which do not originate from human contamination, further explaining why it is difficult to predict and prevent microbiological contamination that generates ropy maple syrup.
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