Welcome  to  the  tartan  Tartar  grade. This  is  a  podcast  brought  to  you  by the  UK  Centre  for  Astroology at  the  University  of  Edinburgh. My  name  is  Mia,  and  I'll  be  interviewing astrobiologists  from  around  the  world about  their  research,  careers,  and  more. This  episode,  we  have  doctor Catherine  Baxter  from the  University  of  Glasgow. Welcome,  doctor  Baxter. Thank  you  so  much  for  being  here today  on  the  tartan  tarta  grade. If  you  could  please  introduce yourself  to  our  listeners, tell  us  who  doctor  Baxter  is. Hello,  thank  you  very  much  for  having  me. My  name  is  Catherine  Baxter. I'm  a  research  associate at  the  University  of  Glasgow. I'm  really  interested  in microbial  community  dynamics  and their  effects  on  pathogenicity and  just  overall  microbial  behaviour. Um,  I'm  currently  working on  a  plant  pathogen, but  I've  done  work  on, um  human  pathogens  recently. Hmm.  That's  great.  Thank  you  so  much. Now,  I  would  love  if  you  could  share your  journey  into  microbiology and  now  your  research  interests evolved  from  how  they evolve  from  cell  wall  integrity in  yeast,  which  is  your  PhD. And  to  now  spacebology. What  motivated  you  to  explore this  intersection  of microbiology  and  spacebology? Um,  I've  always  had  an  interest  in space  ever  since  I  was  younger,  um, and  I've  also  had an  interested  interest  in how  things  work  at  the  molecular  level. Um,  cell  wall  integrity, the  proteins  that  I  worked  on, they  had  been  likened  to similar  sensing  systems  in humans  that  were involved  in  cellular  disease, and  that's  what  kind  of  made me  apply  for  the  post. Um,  of  the  PhD.  And  then after  I  finished  my  PhD, I  moved  into,  um,  industry  and  NHS. And  then  I  missed  research  too  much, and  then  came  back  to  work on  UVB  sensing  in  plants. And  then  I  had  twins. Congratulations. Thank  you.  I  have a  year  of  my  life  I  can't  really remember  I  was  so busy  with  the  kids.  Of  course. And  there  wasn't any  part  time  post  op  positions. Yeah.  So  after  my  contract finished  when  I  come  back  from  maternity, stepped  back  from  research  and  went to  teach  in  further education  at  Ayrshire  College. While  I  was  there,  we did  a  variety  of different  outreach  activities  and one  of  them  was  working  with a  company  called  Iat  and their  mission  discovery  programme. So  that's  where  they  basically  bring  NASA personnel  in  to  work  with fifth  and  sixth  year  students from  high  school. They  give  them  talks,  and  then  they  give them  projects  and  they have  to  come  up  with  a  project to  send  to  the  ISS. So  they  all  work  in  it, and  then  at  the  end  of  the  week, the  panel  judges  them  and the  one  that  wins  gets  to send  the  experiment  to  the  ISS. Oh,  wow.  In  2018, one  of  the  groups  that  I  was  mentoring  won, and  it's  Oh  my  gosh. And  it  wasn't  the  main  one  I  was  mentoring. I  was  going  side  mentoring  this  one and  that  made  me  think  about  research  again. Yeah.  Also  while  I  was  at  the  college, the  UK  Centre  for  Astrobiology had  an  event  for  teachers  to contribute  to  one  of the  programmes  that  they  were developing  and that  kicked  off  my  interest  as  well. At  the  time  when  I  graduated as  an  undergraduate  and then  as  a  postgraduate, um,  there  wasn't  really anything  space  biology  related. Around.  And  so  I  just  there wasn't  any  opportunity.  Yeah. And  it's  only  really  been,  see, in  the  last  kind  of  like  ten  to  15  years 'cause  I  showed  my  age  here. Um,  that  things  have actually  started  to  become available  in  the  UK, previously  it  was  a  case of  you  want  to  do  space  biology? Yeah,  go  to  America. Yeah.  That  makes  sense,  yeah. And  that  just  wasn't  a  path  I  could  choose. Yeah.  And  then,  um, I  taught  for  six  years in  the  Further  Education  college. Again,  I  got  the  itch  to  return  to  research. Yeah. I  applied  to  the  Daphne  Jackson  Trust who  specialise  in fellowship  schemes  for  research  returners. Yeah.  And  I  secured medical  research  Scotland, Daphne  Jackson  Fellowship. So  I  was  funded  for three  years  and  I  had  a  pot  of  money. And  that  got  me  back  into  research. And  basically,  when  I  was  looking  for when  I  was  looking  for  fellowships,  um, Daphne  Jackson  Trust  said,  Look  around, see  what  research  interests  you, approach  people  and  just  see  what  they  say. And  I  was  looking at  the  work  that  was  coming  out  of Gail  McConnell  and  Paul  Hoskinson's  labs at  Strasclyd  looking  at biofilm  formation  with this  fantastic  microscope gives  you  high  resolution over  such  a  wide  field  of  view, and  you  could  just see  so  much  detail  that  you couldn't  see  with  other kind  of  imaging  systems. And  I  dropped  them  an  email, and  we  had  a  conversation  then wrote  a  fellowship  application and  then  got  it. Okay.  And  that  finished  in  October  2023. And  I've  moved  into  the  position  that  I'm in  now  after  a  couple  of  interim  posts. But  during  COVID,  I  saw  a  post on  Twitter  for  the  NASA  star  Okay. Yeah.  Which  is space  flight  technology  applications and  research. Mm  hmm. And  basically,  it  was a  six  month  online  programme  where  you  got to  you  you  went to  seminars  or  online  seminars from  people  who had  flown  space  space  biology  experiments. And  these  were  the people  who  knew  what  to  do. Um,  and  it  was a  fantastic  opportunity  to  speak to  people  who  do  what  I  want  to  do. Yeah.  So  I've  got  a  cohort  of people  that  I  can  now  go  and  talk  to about  space  biology. Yeah.  And  I'm one  of  six  NASA  Star  alumni  in  the  UK. Wow.  Just  now.  Wow.  That's  amazing. I'm  still  in  contact  with people  through this  discuss  so  it's  fantastic. And  through  that,  learned  about the  analysis  working  groups  that are  associated  with  the  NASA Open  Science  Data  Repository. Um,  and  got  involved  with  them, and  it's  been  absolutely  fantastic. They're  great  group  of  people. I'm  now  co  lead  of the  biofilm  subgroup  from the  microbes  Analysis  working  group. I'm  working  towards  writing  a  review. So  it's  been a  very  interesting  winding  journey. Definitely,  yeah. But  I  mean,  there  just hasn't  been  opportunity for  this  kind  of  thing  up  until  recently. Yeah,  that  makes  sense. Yeah.  Thank  you  so  much. Now,  if  you  don't  mind, I  want  to  take  a  moment to  focus  on  your  previous  work  briefly. You  mentioned  that  you  returned  to research  after  a  six  year  break and  you  developed a  new  imaging  method  to  study  biofilms. First,  I'd  love  if  you  could  briefly describe  your  innovation  and would  you  say  that  a  break from  research  gave  you a  new  perspective  that allowed  you  to  make  this  innovation? Okay. Yes.  So  the  first  part  of  that  question. So  the  methodology  that  I developed  was  using  the  mesa  lens. Yes. Which  is  this  bespoke  microscope  that  um, has  very  low  magnification  objective  lens, but  it  has  a  very  high  numerical  aperture, which  means  that  you  can  visualise a  large  field  of  view with  subcellular  resolution. So  you  can  the  biofilms  that  I  was imaging  were  like  3  millimetres  in  diameter, and  you  can  basically  you  can zoom  in  and  see  the  individual  cells. It's  beautiful. Um,  and  so  I  applied a  change  to  the  method  that  had  already  been established  because I  was  finding  previously  previously, we  would  mount  the  biofilms  on the  agar  surface  and  then  coat  it  with  water. And  what  I  was  finding was  my  biofilms  are  floating  away. I  don't  know.  I  couldn't use  water  immersion  to  see  them. I  see.  And  so I  had  to  think  of  a  different  way. And  so  I  basically cast  a  small  amount  of  vagar  onto a  cover  slip  and  then  spotted the  cultures  for  the  biofilm  growth  on that  and  then  imaged  through  the  cover  slip. Which  meant  that  because  I  wasn't disrupting  the  biofilms  by exposing  them  to  water over  a  long  period  of  time. Could  follow  the  biofilm  formation over  a  longer  period  of  time. Wow.  I  basically  spot  them  onto the  surface  and  then  every so  often,  taking  the  image, and  I  could  just  basically  see  how the  biofilm  structure develops  over  time.  Yes. Yeah,  that's  great.  Thank  you  very  much. And  do  you  think  that the  six  year  break  gave  you a  new  perspective  that benefited  your  work?  I  think  so. Because  previously  it  prior to  the  career  break? I've  been  working  in  plant  science. Okay.  To  be  fair,  I'm  back in  plant  science.  Um So  this  was  it  was  more  of  a  nod  to  my  PhD. Rather  than  what  I've been  doing  as  my  postdoc. Right.  Because  I  was  looking  at  how, um,  the  key  signalling  molecule,  um, in  plants  the  mechanism  of  its  action, which  was  there  was  there  was  similarities  to my  PhD  in  the  technologies that  was  using  and  methodologies. But  having  the  break  meant  it  was  like, I  could  go  do  anything and  I  could  go  do something  that  I  found  really, really  interesting. Yeah,  definitely.  I  was  like, I  think  if  you're  a  postdoc, you  can  have  you  work  for  somebody and  and  do  somebody's  research. Yeah,  it  interests  you,  as  well, because  that's  why  you've  got  the  job. Right.  But  it  gave me  an  opportunity  to  drive  my  own  research. Yeah.  And  now,  like, my  ultimate  career  goal  is to  be  an  independent researcher  is  to  have  my  own  group. And  I'm  trying  to  move  to the  independence  because,  I  mean, the  fellowship,  I  came  up  with the  idea  and  drove  the  research. And  so  it's  mine. And  so,  to  be  able  to  explore things  around  the  area  that  I've  chosen, it's  like  it's  exciting  in  the  privilege? Definitely.  Yeah,  very  inspiring. Thank  you  very  much. Now,  I  saw  that  your  current  work  involves investigating  the  impact  of microgravity  on  skin  microorganisms. So  tell  us  a  bit  more  about  this  research  and its  impact  for  astrobiology.  Okay. So  every  time  we go  into  space,  microbes  go  with  us. They  have  been  going  with  us  since we've  been  going  into  space. I  don't  think  we  really can  appreciate  just  how much  they've  been  on the  same  journey  as  we  have.  Mm  hm. And  every  time  somebody  goes  into  space, they  take  what's their  own  microbiome  with  them. Yeah.  Their  microbiome  is  exposed  to the  same  space  flight  stressors as  the  body  is. Yeah.  Okay.  And  so  I  know, we  know  that  an  awful  lot  of  um, physiological  changes happen  during  spaceflight. We  don't  know  to  what  degree, sort  of  microbial  physiology  changes. Yeah.  And  so  looking  at the  combination  of two  components  of  the  skin  microbiome, very  different  because  one's a  bacterium  and  one's  a  fungus, seeing  how  they  interact and  behave  because  traditionally, when  we  explore  microorganisms  in  the  lab, we  grow  them  individually  under very  non  natural  conditions. Yeah.  And  so  you  tend  to  find  that  in  nature, microorganisms  live  in  these  big  kind  of multi  species  inter kingdom  communities  where  you get  fungi,  bacteria,  viruses,  archaea. Everything's  in  there, and  we  don't  really  appreciate  that. And  we  don't  really  investigate.  Mm  hm. And  so  by  looking  at very  it's  clinically  relevant in  that  it  causes  infections  on  Earth. But  it's  also  a  small  snippet of  what multi  species  microbial community  may  behave  like. And  so  using  something that  we're  kind  of  familiar  with to  explore  what  happens under  spaceflight  conditions will  inform  both  not  just  skin  microbiome, form  gut  microbiome. Um,  plant  microbiome, microbiome  with  a  built  environment. All  the  microbiomes. Yeah.  Very  cool. So,  yeah,  it  has  Yeah. Long  and  reaching  implications, even  though  it's  just  like  two  be  bugs. Yeah,  definitely.  Thank  you  very  much,  yeah. So, are  there  any  unexpected or  surprising  results that  have  implications  for both  space  and  Earth  based  medicine? So  one  of  the  kind  of  analogies  of  analogues, really,  between  parallels between  spaceflight  and  terrestrial. Microbial  growth  is  shear  stresses. And  so,  in  microgravity, you  have  low  shear  stress. Yeah.  And  within  the  body, your  cardiovascular  system  has a  range  of  different  shear  stresses. You  have  high  shear  stress in  the  areas  where,  let's  say, like  your  arteries  because the  blood  has  been pumped  forced  through  them. And  then  you  get  to  regions  where  you've  got a  low  shear  stress towards  capillaries  and  that  kind  of  thing. And  so  you've  got  a  huge variety  of  shear  stresses within  the  body  that  the microorganisms  have  to  respond  to. And  again,  we  don't  really  know  how much  that  impacts  their  behaviour. It  may  kind  of  augment things  towards  virulence. It  may  not.  We  just  don't  know. Um,  and  being  able  to  look  at  behaviour  in a  similar  shear  stress  environment has  kind  of  implications for  all  of  it  behaves like  this  under lociar  stress  in  these  conditions. Yeah.  Is  it  going  to behave  under  lociar  stress  in  the  body? So  we  have  seen  you  get, these  kind  of  long  hype  big  long  kind of  rod  light  structures  produced  by  Candida. Mm  hm.  Does  that happen  in the  lousier  stress  areas  of  the  body? Yeah.  Interesting.  Yeah.  Thank  you. So  with  upcoming  long  term  missions to  the  moon  and  Mars, what  do  you  think  are the  biggest  challenges  we  face  in maintaining  astronaut  health from  a  microbiological  perspective? I  think  it's  from  your  own  microbiome. Okay.  I  saw  an  awful  lot  of  people  with underlying  health  conditions  infections caused  by  the  bugs  that  they're  carrying. Okay.  And  so  if  you  are  in an  environment  where  your  health  is severely compromised  for  a  long  period  of  time, then  you're  going  to get  you're  going  to get  re  emergence  of  infections, you're  going  to  get  infections where  you  wouldn't  normally get  infections  on  earth. Mm  hmm.  Mm  hm,  and so  you're  going  to  be  in  a  situation  where, yeah,  you  get  to  Mars. Yeah.  But  are  you actually  physically  fit  enough  to  go  on the  surface  and  is  your  microbiome  going to  be  in  a  fit  state  to  help  you?  Yeah. Or  is  it  going  to  be  in  a  state  that's  going to  severely compromise  your  ability  to  function? Oh,  wow.  We  don't  know. Yeah.  I  just  don't  know. Wow.  Really?  That's  amazing. Yeah.  Your  microbiome  supports you  in  so  many  different  ways.  That's  crazy. It's  like  it's  key to  your  health  and it's  implicated  in so  many  chronic  conditions. Yeah.  No,  that  totally  makes  sense. I  feel  like  when  we  talk  about these  potential  colonies  on  other  planets, we  think  about  a  lot  of  things, how  we're  going  to  get  there,  how  we're going  to  live  there,  that  sort  of  thing. We  don't  really  think about  these  kinds  of  things,  you  know, how  the  human  microbiome  could  potentially affect  the  astronauts  that we  send  there  and  that  sort  of  thing. Yeah,  thank  you  so  much  for  giving  that  for. It's  not  also  the  human  microbiome  though because  it's  like  you  plant  health  as  well. Yeah,  that's  true. Microorganisms  underpin  everything. Everything.  Everything.  I  don't  think people  appreciate  just  how much  climate  change is  going  to  affect microorganisms  that  basically support  everything  on  Earth. Wow,  yeah.  If  you  are  basically compromising  your  microbial  life  support. Then  that's  a  serious  issue  that  you  have  to think  about and  develop  countermeasures  against  it. Yeah,  that  makes  sense. And  do  you  ever  think  about potential  microbes  that  are maybe  living  on  Mars  and  how  that  if, say,  we  were  to  go, how  that  could  potentially  affect us  or  I  don't  know. I  don't  know  what  do  you  think  about  that? I  don't  know  how  well,  they  would  infects. Okay.  Although  in  saying that  severely  immunocompromised  patients, you  get  random  infections  with things  that  you  would  never  cause  infections. Okay.  I  may  be  a  case  of  it's  just, um,  uh, the  wrong  microorganism  at  the  wrong  time. Um,  in  that  kind  of,  like,  terms. I'm  more  worried  about, what's  luring  in  the  Yeah, in  the  permafrost, that's  defrosting  just  now. Yeah,  true,  true.  Rather  than what's  on  Mars,  but  excuse  me. I  don't  know  what's gonna  we'll  find  when  we  go  there. No,  that's  very  true. That's  very  true.  I  was  just  curious. And  one  question  I  had  for  you  was once  you  are  to  become an  independent  researcher with  your  own  group, what  is  the  first  thing  that  you want  to  do  for  your  research? Oh,  that's  a  very  good  question. I'd  have  to  think  about  that. Of  course,  yeah,  take  your  time. Um,  I  want  to  buy  lots  of  small, um,  uh, disposal  rotating  wall  vessels  and  just  grow everything  under  simulate  my  gravity. That  sounds  really  cool,  yeah. I  don't  know  if  I'd  get  the  funding  for  it. That's  something  I  just  have  to  do in  the  QT.  Yes. No,  that  sounds  great.  No,  I was  just  curious  about  that. But  that's  great,  yeah. One  of  the  things  I  would  like  to do  Sure  is  look at  microbial community  dynamics  systematically. Okay.  Because  biofilms  are basically  an  optimal  output for  a  set  of  given  conditions.  Mm  hmm. And  if  we  could develop  a  method  that  we  could predict  biofilm  formation  from,  like, environmental  and  kind  of  internal  telemetry. Then  you  could  start  kind  of  designing treatments  and  things  should be  great.  I'd  love  to  be  able  to  explore. Okay,  great. Yeah,  that's  very  interesting.  Thank  you. I  think  that's  long  term. Yeah.  That  makes  sense.  No  for  sure. And  good  luck.  I  hope  you  are to  get  your  own  group  one  day. That  would  be  amazing. Thank  you.  And  finally, do  you  have  any  advice  for potential  listeners  who  are interested  in  pursuing  a  similar  field in  space  microbiology? Ask  lots  of  questions,  and  don't  be  afraid  to be  the  only  person  that's interested  in  your  research  environment. If  you  get  funny  looks,  that  doesn't  matter. You  might  end  up sending  something  to  the  moon, so  now  you  can  go  there. Da  da.  Don't  be  afraid.  Reach  out. There  are  a  space  biology. There  are  others  that  are  interested  in space  biology  around  the  UK. You  just  have  to  find  them. Yeah,  definitely. Great.  Thank  you  so  much,  doctor  Baxter, for  being  with  us  today,  and for  being  on  the  Tard  and  tart  grade, it  was  very  nice  to  chat  with  you. Thanks  much  for  having  me.  Thank  you.